Learn Once, Earn Repeatedly The Crypto Revolution of Knowledge

Allen Ginsberg
8 min read
Add Yahoo on Google
Learn Once, Earn Repeatedly The Crypto Revolution of Knowledge
Ultimate Guide to NFT Opportunities for Institutional ETF Opportunities 2026
(ST PHOTO: GIN TAY)
Goosahiuqwbekjsahdbqjkweasw

The digital age has ushered in an era of unprecedented access to information. With a few clicks, we can delve into subjects that once required years of formal schooling, traverse the globe through virtual tours, and connect with experts from every corner of the planet. Yet, despite this abundance of knowledge, the traditional model of education often leaves us with a lingering question: what's next? We invest time, effort, and often significant financial resources into acquiring new skills and understanding, only to see that initial spark of learning fade without a clear, ongoing benefit. What if learning itself could become a source of continuous reward, a wellspring of passive income that replenishes itself as your knowledge base grows? This is the core promise of the "Learn Once, Earn Repeatedly" (LORE) paradigm, a revolutionary concept gaining traction within the vibrant and ever-evolving world of cryptocurrency and blockchain technology.

Imagine a future where your pursuit of knowledge isn't a finite transaction but a dynamic, ongoing relationship with value creation. This isn't science fiction; it's the tangible reality being built today through innovative applications of decentralized technologies. At its heart, the LORE model leverages the inherent properties of blockchain – transparency, security, and the ability to facilitate peer-to-peer transactions without intermediaries – to create incentivized learning ecosystems. Think of it as a digital renaissance, where curiosity is the currency and the rewards are as enduring as the knowledge itself.

The foundational shift lies in reimagining the very concept of educational assets. In the traditional sense, knowledge is largely intangible and its monetization often indirect, reliant on job markets or intellectual property. However, within the Web3 space, this knowledge can be tokenized, allowing for direct rewards and ownership. When you learn a new skill, master a complex concept, or contribute valuable insights, these achievements can be recognized and rewarded with digital assets, often in the form of cryptocurrency or non-fungible tokens (NFTs). This isn't just about receiving a certificate; it's about holding a tangible, valuable asset that represents your acquired expertise.

Consider the implications for lifelong learning. The fear of obsolescence in a rapidly changing world is a pervasive concern. The LORE model directly addresses this by creating a continuous loop of engagement and reward. You learn a new programming language, for instance. Through a LORE platform, your proficiency could be validated, earning you tokens that can then be used to access further, more advanced courses, or even traded for other cryptocurrencies. As you continue to learn and upskill, your portfolio of earned assets grows, creating a direct financial incentive to remain engaged and adaptable. This transforms learning from a potential burden into an ongoing opportunity for wealth creation.

The beauty of this system lies in its potential for passive income. Once you’ve acquired a certain skill or understanding, the system can be designed to reward you repeatedly for that foundational knowledge. This might manifest as staking your learned expertise to validate information on a decentralized network, contributing to a decentralized autonomous organization (DAO) where your specialized knowledge is valuable, or even receiving royalties when your educational content is utilized by others within the ecosystem. This move from active earning (trading time for money) to more passive income streams is a cornerstone of financial freedom for many, and LORE offers a unique pathway to achieve it through intellectual capital.

Moreover, the decentralized nature of these learning platforms democratizes access and ownership. Unlike traditional educational institutions that can be prohibitively expensive and geographically limited, LORE platforms are often globally accessible and built on open protocols. This means anyone with an internet connection can participate, learn, and earn, leveling the playing field and fostering a more inclusive global knowledge economy. The barriers to entry are significantly lower, allowing talent and dedication to shine regardless of background.

The underlying technology, blockchain, is crucial here. It provides the secure, transparent ledger that tracks learning achievements, manages token distribution, and ensures the integrity of the entire system. Smart contracts, self-executing agreements written in code, automate the reward mechanisms, ensuring that participants are fairly compensated for their efforts and contributions. This eliminates the need for a central authority to verify learning and distribute rewards, reducing overhead and increasing efficiency.

The "Learn Once, Earn Repeatedly" ethos is more than just a catchy slogan; it’s a fundamental reimagining of how we acquire, value, and utilize knowledge in the digital age. It’s about empowering individuals to not only expand their minds but also their financial horizons, creating a virtuous cycle where intellectual growth directly translates into tangible, lasting rewards. As we delve deeper into the specifics of how this model is being implemented, the transformative potential becomes increasingly clear. The future of learning is not just about acquiring knowledge; it's about owning it, leveraging it, and letting it work for you, again and again.

The shift from traditional educational models to a LORE framework represents a paradigm shift akin to the advent of the internet itself. For centuries, learning has been a somewhat linear process: acquire knowledge, apply it for a period, and then, often, re-engage in learning to stay relevant. The LORE model fractures this linearity, creating a system where initial learning investment yields compounding, ongoing returns. This is achieved through various innovative mechanisms built upon blockchain technology.

One of the most prominent implementations of LORE is seen in the "Learn-to-Earn" (L2E) model, which is rapidly gaining momentum. Platforms are emerging that reward users with cryptocurrency for completing educational modules, quizzes, and even for engaging in discussions related to specific topics. This might be learning about the intricacies of Bitcoin, understanding the principles of decentralized finance (DeFi), or mastering a new coding language. Upon successful completion and validation of their understanding, users receive tokens. These tokens are not just virtual points; they are real digital assets that hold actual value.

What makes this "earn repeatedly" aspect so powerful is the inherent utility of these earned tokens. They can often be used within the same ecosystem to access premium content, subscribe to advanced courses, or gain membership in exclusive learning communities. This creates a self-sustaining loop where your initial learning directly fuels your continued education. Furthermore, these tokens can be traded on cryptocurrency exchanges, offering users the flexibility to diversify their holdings or liquidate their earnings. This direct link between educational achievement and financial gain is a potent motivator, driving engagement and fostering a deeper commitment to learning.

Beyond simple completion, the LORE model can also reward ongoing engagement and contribution. Imagine a decentralized knowledge base where users can contribute articles, tutorials, or answer questions. Through a well-designed tokenomics system, these contributions can be upvoted and validated by the community, earning the contributors tokens. This incentivizes the creation of high-quality, relevant educational content, fostering a collaborative learning environment where the collective knowledge of the community grows, and every contributor benefits. This is a direct application of decentralized governance and reward systems to the realm of education.

The concept of NFTs also plays a crucial role in LORE. An NFT can represent a specific learning achievement, a mastery of a particular skill, or even a unique educational insight. Holding such an NFT could grant holders ongoing benefits, such as access to future courses related to that skill, participation rights in decision-making processes within a decentralized educational organization, or even a share of revenue generated from the use of that knowledge. For instance, an NFT representing mastery of a particular blockchain protocol might grant the holder a small percentage of transaction fees processed by that protocol or a share of revenue from educational content created about it. This moves beyond a one-time reward to a persistent ownership stake tied to your learned expertise.

The implications for various sectors are profound. For developers, learning a new blockchain framework could lead to earning tokens that can be staked to validate transactions on that network, or used to purchase development tools. For artists, understanding NFTs and the metaverse could lead to earning tokens that grant them access to virtual gallery spaces or the ability to mint their own digital art. For educators, creating and sharing valuable learning materials within a LORE ecosystem could lead to ongoing royalties based on the usage and impact of their content.

The "Learn Once, Earn Repeatedly" model fundamentally shifts the locus of control back to the learner. Instead of being passive recipients of information, individuals become active participants in a knowledge economy where their intellectual capital is directly valued and rewarded. This democratizes not only access to education but also the ability to generate wealth from it, breaking down traditional economic barriers and fostering a more equitable distribution of opportunity. It's a vision where curiosity is a powerful engine for financial empowerment, and the pursuit of knowledge is intrinsically linked to personal and economic growth. This first part has laid the groundwork for understanding the "what" and "why" of this revolutionary concept.

The true magic of the "Learn Once, Earn Repeatedly" (LORE) model unfolds when we move beyond the theoretical and explore its practical implementations and the profound societal shifts it portends. This isn't just about receiving a few crypto tokens for completing a module; it's about building a sustainable financial ecosystem around the very act of acquiring and applying knowledge. The key lies in the intelligent design of tokenomics and the leveraging of decentralized technologies to create persistent value streams for learners.

One of the most exciting frontiers for LORE is within the realm of Decentralized Autonomous Organizations (DAOs). These are community-governed entities that operate without central leadership. Many DAOs are formed around specific projects, industries, or even educational goals. Within a LORE-focused DAO, members who acquire and demonstrate expertise in the DAO’s area of focus can be rewarded with governance tokens. These tokens not only grant voting rights on the DAO's future direction but also often entitle holders to a share of any profits generated by the DAO. For example, a DAO focused on advancing blockchain interoperability might reward members who learn about and contribute solutions for cross-chain communication. Once they've "learned once," their expertise can be repeatedly leveraged within the DAO, earning them tokens for their ongoing contributions, problem-solving, and validation of new ideas. This creates a powerful incentive for continuous learning and active participation.

Consider the implications for professional development. Traditionally, upskilling might involve costly certifications or training programs with no guarantee of immediate financial return. In a LORE environment, a professional learning a new data analysis technique could earn tokens for mastering the skill. These tokens could then be used to access specialized software tools, subscribe to industry reports, or even be staked within a professional network that rewards collaborative problem-solving. As their expertise grows and they apply it to real-world challenges, their ability to earn through the LORE model expands. The initial learning investment becomes a perpetual asset, continually generating value as the professional remains at the cutting edge of their field.

The concept of "proof of learning" is central to the LORE model's ability to ensure repeated earning. This goes beyond simple course completion. Sophisticated systems are emerging that use blockchain to verify not just that someone has gone through the material, but that they have genuinely understood and can apply it. This might involve complex quizzes, project-based assessments, or even peer-validation mechanisms. Once this "proof of learning" is established and recorded on the blockchain, it becomes a verifiable credential that can be leveraged for ongoing rewards. This ensures that the "earn repeatedly" aspect is tied to genuine, retained knowledge and skill, rather than superficial engagement.

Furthermore, the LORE model can foster a dynamic intellectual property market. Imagine a creator who develops an innovative educational course on a complex topic, like quantum computing. By embedding LORE principles, this creator can tokenize their course, allowing learners to purchase access with cryptocurrency. More importantly, the creator can also earn repeatedly. As learners engage with the course and demonstrate mastery, they might earn tokens. These tokens could then be used to access advanced modules, or even grant the learner a small percentage of future revenue generated by that course if they actively promote it or contribute valuable feedback. This incentivizes creators to produce high-quality, impactful educational content, knowing that their initial effort can lead to sustained income.

The potential for democratizing access to high-value skills is immense. Think of individuals in developing nations who may not have access to traditional university education but possess immense potential. Through LORE platforms, they can learn in-demand skills – coding, digital marketing, AI prompt engineering – and earn cryptocurrency that can improve their quality of life, invest in further education, or even bootstrap their own businesses. The global reach of blockchain technology means that these opportunities are not confined by geographical boundaries, fostering a more equitable distribution of knowledge and economic empowerment on a global scale.

The "Learn Once, Earn Repeatedly" ethos also encourages a culture of continuous improvement and knowledge sharing. Instead of hoarding knowledge for fear of devaluing it, the LORE model incentivizes sharing and collaboration. When you teach someone else, or contribute to a shared knowledge base, you are often rewarded. This creates a positive feedback loop: the more you share, the more you learn, and the more you earn. This contrasts sharply with traditional models where knowledge can become a competitive advantage that is guarded closely.

Looking ahead, the integration of Artificial Intelligence (AI) with LORE promises even more sophisticated applications. AI can personalize learning paths, identify knowledge gaps, and even dynamically adjust reward mechanisms based on individual progress and market demand for specific skills. Imagine an AI tutor that not only teaches you but also helps you identify how your newly acquired skills can be leveraged for maximum earning potential within the LORE ecosystem, potentially suggesting opportunities to stake your knowledge or contribute to specific projects that align with your expertise.

The journey from learning to earning is being fundamentally redefined. The "Learn Once, Earn Repeatedly" model, powered by cryptocurrency and blockchain, is not just an educational innovation; it's an economic revolution. It offers a path to financial empowerment rooted in intellectual growth, a future where curiosity is rewarded, and knowledge becomes a lifelong source of sustainable income. It's an invitation to invest in yourself, knowing that the returns are not just potential job prospects, but tangible, digital assets that can grow and generate value, time and time again. This paradigm shift is well underway, and its implications for individuals and society are only beginning to be fully understood.

In the ever-evolving landscape of technology, quantum computing stands as one of the most exciting frontiers, promising to revolutionize industries from cryptography to pharmaceuticals. Yet, the very power that fuels quantum computing also poses a formidable threat to current encryption methods. This is where quantum-resistant technology comes into play. For beginners stepping into the realm of AI-integrated projects in 2026, understanding quantum-resistant systems is not just beneficial—it’s essential.

The Quantum Challenge

Quantum computing leverages the principles of quantum mechanics to process information in ways that classical computers cannot. While this capability holds the promise of solving complex problems at unprecedented speeds, it also threatens to render many existing encryption methods obsolete. Traditional cryptographic algorithms, which secure our digital communications, could be easily broken by quantum computers.

This impending threat has spurred the development of quantum-resistant algorithms. These are designed to withstand the computational power of quantum computers, ensuring that data remains secure even in a future where quantum computing is mainstream. For AI-integrated projects, the stakes are particularly high. The fusion of artificial intelligence and quantum computing could lead to breakthroughs that reshape our world, but only if the security aspects are meticulously managed.

Why Quantum-Resistant is Crucial

AI-integrated projects often involve vast amounts of sensitive data. Whether it's personal information, trade secrets, or national security data, the potential for misuse is enormous. Quantum-resistant technology ensures that this data remains protected against the dual threats of current cyber-attacks and future quantum threats.

Imagine an AI-driven healthcare system. Such a system would handle sensitive patient data, from genetic information to medical histories. Without robust quantum-resistant encryption, this data could be vulnerable to both conventional hackers and future quantum adversaries. Thus, integrating quantum-resistant systems into AI projects isn’t just a technical necessity—it’s a moral imperative.

The Building Blocks of Quantum-Resistant Technology

At its core, quantum-resistant technology revolves around a few key concepts and algorithms. These include lattice-based cryptography, hash-based cryptography, multivariate polynomial cryptography, and code-based cryptography. Each of these approaches offers unique advantages and challenges.

Lattice-Based Cryptography

Lattice-based cryptography is one of the leading contenders in the race for quantum-resistant solutions. It relies on the hardness of certain mathematical problems, even for quantum computers. This method provides a strong foundation for secure communication and data integrity.

Hash-Based Cryptography

Hash-based cryptography focuses on creating secure, one-way functions that are incredibly difficult to reverse, even for quantum computers. These functions ensure that data remains tamper-proof, making them invaluable for securing transactions and communications.

Multivariate Polynomial Cryptography

This approach uses systems of multivariate polynomials to create cryptographic keys. The complexity of solving these polynomial systems makes them a formidable challenge for quantum computers, offering a robust layer of security.

Code-Based Cryptography

Code-based cryptography leverages error-correcting codes to generate secure keys. These codes are based on the difficulty of decoding random linear codes, which quantum computers find particularly challenging.

Practical Integration

Integrating quantum-resistant algorithms into AI projects involves a few strategic steps. First, it’s crucial to identify the data that needs the most protection. This includes sensitive personal data, proprietary information, and critical infrastructure data.

Once identified, the next step is to select the appropriate quantum-resistant algorithm based on the specific requirements and constraints of the project. This might involve a mix of the aforementioned cryptographic approaches, tailored to the project’s unique needs.

Testing and validation are also key. Rigorous testing ensures that the integrated system performs efficiently and securely. This involves both classical and quantum simulations to validate the system’s resilience against both current and future threats.

The Future is Now

While quantum computing is still in its nascent stages, its potential is undeniable. By adopting quantum-resistant technology early, beginners in AI-integrated projects can future-proof their work, ensuring that it remains secure and relevant in the face of technological advancements.

In the world of quantum-resistant technology, staying ahead of the curve means being proactive rather than reactive. For beginners, this means not just learning the technical aspects but also understanding the broader implications of their work. It’s about building a foundation that’s not only strong today but also resilient for tomorrow.

Navigating the Quantum Frontier

As we delve deeper into the future of quantum-resistant technology for AI-integrated projects, it’s essential to understand the practical steps and considerations for implementation. This second part of our exploration will guide you through advanced concepts, real-world applications, and the evolving landscape of quantum security.

Advanced Quantum-Resistant Algorithms

While the foundational algorithms—lattice-based, hash-based, multivariate polynomial, and code-based—form the bedrock of quantum-resistant technology, there’s a growing field of advanced algorithms that are pushing the boundaries of what’s possible. These include hybrid cryptographic systems that combine the strengths of multiple approaches.

Hybrid Cryptographic Systems

Hybrid systems merge different cryptographic methods to create a more robust security framework. For instance, combining lattice-based and hash-based cryptography can offer a dual layer of protection. This approach is particularly useful in AI-integrated projects where data security is paramount.

Post-Quantum Cryptography Standards

Organizations like the National Institute of Standards and Technology (NIST) are at the forefront of developing post-quantum cryptography standards. These standards aim to establish a global framework for quantum-resistant algorithms, ensuring that they are both secure and practical for real-world applications.

Implementing Quantum-Resistant Systems

Implementing quantum-resistant systems in AI projects involves careful planning and execution. Here’s a step-by-step guide to help you navigate this complex process:

Step 1: Assess Security Needs

Begin by assessing the security needs of your project. Identify the types of data that require protection and the potential threats they face. This includes both current cyber threats and future quantum threats.

Step 2: Choose the Right Algorithms

Select quantum-resistant algorithms that best fit your project’s requirements. Consider factors like computational efficiency, security strength, and compatibility with existing systems.

Step 3: Integrate and Test

Integrate the chosen algorithms into your AI project. This involves modifying existing codebases or developing new modules. Rigorous testing is crucial to ensure that the new system performs efficiently and securely.

Step 4: Continuous Monitoring and Updates

Security is an ongoing process. Continuously monitor the system for vulnerabilities and update it as new quantum-resistant algorithms and standards emerge. This proactive approach ensures that your project remains secure in the face of evolving threats.

Real-World Applications

To illustrate the practical applications of quantum-resistant technology, let’s explore a few real-world examples:

Healthcare

In healthcare, quantum-resistant encryption can protect sensitive patient data, ensuring that personal health information, genetic data, and medical histories remain secure against both current and future threats. This is particularly important as AI systems become more integrated into healthcare, handling vast amounts of sensitive data.

Finance

The financial sector is another critical area where quantum-resistant technology is essential. Quantum-resistant encryption can safeguard financial transactions, customer data, and proprietary trading algorithms, ensuring that the integrity and confidentiality of financial data are maintained.

Government and Defense

Government and defense projects often handle highly sensitive information. Quantum-resistant encryption can protect national security data, military communications, and confidential government documents, ensuring that they remain secure against both conventional and quantum threats.

Emerging Trends

The field of quantum-resistant technology is rapidly evolving, with several emerging trends that are shaping its future:

Quantum Key Distribution (QKD)

Quantum Key Distribution uses the principles of quantum mechanics to create secure communication channels. Unlike traditional encryption methods, QKD ensures that any attempt to intercept the key results in detectable changes, making it nearly impossible for quantum computers to break.

Quantum-Safe Blockchain

Blockchain technology is another area where quantum-resistant technology is making significant inroads. Quantum-safe blockchain uses quantum-resistant algorithms to secure transactions and ensure the integrity of the blockchain, making it resilient against future quantum attacks.

Quantum-Resistant AI

AI itself is also becoming quantum-resistant. By integrating quantum-resistant encryption into AI systems, developers can ensure that AI models and data remain secure, even in a post-quantum world.

Looking Ahead

As we look to the future, the importance of quantum-resistant technology in AI-integrated projects cannot be overstated. The potential of quantum computing to revolutionize technology is matched only by its threat to current cryptographic systems. By adopting quantum-resistant technology early, beginners can ensure that their projects are secure, resilient, and future-proof.

The journey into quantum-resistant technology is just beginning. For beginners, it’s a path filled with opportunities to innovate, protect, and shape the future of secure digital communication. By embracing this technology, you’re not just participating in the next wave of technological advancement—you’re ensuring that it’s a wave that carries us forward securely and responsibly.

Emerging Innovations and Future Directions

As we continue to explore the captivating world of quantum-resistant technology for AI-integrated projects, it’s vital to look ahead to the innovations and future directions that promise to shape this field. This part will delve into the cutting-edge developments, emerging trends, and the visionary future of quantum-resistant systems.

The Quantum Leap in Cybersecurity

The concept of quantum computing and its potential to disrupt traditional cryptographic methods has been a game-changer in cybersecurity. Quantum-resistant technology is the response to this challenge, aiming to secure data and communications against the computational prowess of quantum computers.

Quantum computers leverage quantum bits (qubits) to perform calculations at speeds unattainable by classical computers. This capability allows them to solve complex problems that are currently infeasible. For example, Shor’s algorithm can factor large numbers exponentially faster than the best-known classical algorithms, posing a significant threat to RSA encryption—a widely used method for securing data.

Quantum-Resistant Algorithms in Action

Let’s delve deeper into how quantum-resistant algorithms are being implemented and their effectiveness:

Lattice-Based Cryptography

Lattice-based cryptography is gaining traction due to its robustness against quantum attacks. Algorithms like NTRUEncrypt and Learning With Errors (LWE) are examples that have shown promising results in both theoretical and practical settings. These algorithms are based on the difficulty of solving lattice problems, which quantum computers find intractable.

Hash-Based Signatures

Hash-based signatures, such as XMSS (eXtended Merkle Signature Scheme), provide a quantum-resistant alternative to traditional digital signatures. These signatures are based on hash functions and Merkle trees, ensuring that they remain secure even in a post-quantum world.

Multivariate Polynomial Cryptography

Multivariate polynomial cryptography uses systems of multivariate polynomials to generate cryptographic keys. The complexity of solving these systems makes them a formidable challenge for quantum computers. Algorithms like Rainbow and HFE (Hidden Field Equations) exemplify this approach.

Code-Based Cryptography

Code-based cryptography relies on the difficulty of decoding random linear codes. McEliece and Niederreiter are two well-known code-based cryptographic systems that have shown resilience against quantum attacks.

Real-World Implementations

To understand the practical applications of quantum-resistant technology, let’s explore some real-world examples:

Healthcare

In healthcare, quantum-resistant encryption can protect sensitive patient data, ensuring that personal health information, genetic data, and medical histories remain secure against both current and future threats. This is particularly important as AI systems become more integrated into healthcare, handling vast amounts of sensitive data.

Finance

The financial sector is another critical area where quantum-resistant technology is essential. Quantum-resistant encryption can safeguard financial transactions, customer data, and proprietary trading algorithms, ensuring that the integrity and confidentiality of financial data are maintained.

Government and Defense

Government and defense projects often handle highly sensitive information. Quantum-resistant encryption can protect national security data, military communications, and confidential government documents, ensuring that they remain secure against both conventional and quantum threats.

Emerging Trends

The field of quantum-resistant technology is rapidly evolving, with several emerging trends that are shaping its future:

Quantum Key Distribution (QKD)

Quantum Key Distribution uses the principles of quantum mechanics to create secure communication channels. Unlike traditional encryption methods, QKD ensures that any attempt to intercept the key results in detectable changes, making it nearly impossible for quantum computers to break.

Quantum-Safe Blockchain

Blockchain technology is another area where quantum-resistant technology is making significant inroads. Quantum-safe blockchain uses quantum-resistant algorithms to secure transactions and ensure the integrity of the blockchain, making it resilient against future quantum attacks.

Quantum-Resistant AI

AI itself is also becoming quantum-resistant. By integrating quantum-resistant encryption into AI systems, developers can ensure that AI models and data remain secure, even in a post-quantum world.

The Visionary Future

Looking ahead, the future of quantum-resistant technology is brimming with possibilities. As quantum computing technology matures, the need for quantum-resistant systems will only grow. Innovations in quantum-resistant algorithms, combined with advancements in AI and blockchain, promise to create a more secure digital landscape.

For beginners in the field, the journey into quantum-resistant technology is not just about keeping up with technological advancements—it’s about being at the forefront of a revolution that promises to redefine the boundaries of cybersecurity. By embracing this technology, you’re not just participating in the next wave of technological advancement—you’re ensuring that it’s a wave that carries us forward securely and responsibly.

In conclusion, quantum-resistant technology represents a critical pillar in the architecture of future-proof AI-integrated projects. It’s a field ripe with opportunities for innovation, security, and progress. As we continue to navigate this exciting frontier, the promise of a secure, resilient digital future becomes ever more tangible.

Unlocking Financial Freedom_ The Allure of Tokenized Treasuries with 5%+ Safe Yields

Exploring the World of Smart Contract Security Jobs_ Part 1

Advertisement
Advertisement