This document discusses different business models and monetization strategies for mobile apps. It begins by defining monetization and business models, then outlines common models like in-app advertising, purchases, freemium, and subscription. Non-traditional models like incentivized downloads and premium SDKs are also covered. The timing of monetization is addressed, noting the tradeoff between early monetization through pay-per-download versus optimizing revenue over time from a larger user base. The document wraps up by advising app creators to pick the best strategy and explore new models, while only monetizing once the user base is large enough.