Passive income: NO

Earning passive income solely from an AI Audio Book Review and Recommendation Engine side hustle is unlikely for most individuals. While there is potential for passive income through this venture, it typically requires a significant amount of setup and ongoing maintenance to automate processes and ensure accurate recommendations. Setting up automation tools, implementing machine learning algorithms, and continuously updating the system are crucial for long-term success. However, achieving true passivity where income flows consistently without active involvement is rare and usually attained by a few outliers with advanced technical skills and resources. Most people may find themselves needing to actively manage and optimize the system regularly to maintain profitability. It's important to set realistic expectations regarding the level of passive income achievable through this side hustle.