The document discusses how to make money by creating and selling modules on Appcelerator's open marketplace. It describes what modules are (extensions that add functionality to mobile apps), provides statistics on the marketplace's size and growth, and gives examples of top-selling modules. It then explains how to create a module, market it on the marketplace, use it to promote a company or apps, wrap existing APIs into modules, and monetize apps with advertising modules. The document advises thinking about features, pricing, categorization, and support when setting up a module on the marketplace.