Ads should be relevant to the content of mobile app. Content should be the driving force to serve ads. That is the basic idea of Content-Driven In-App Advertising (CDIAA).
Here is an example. You scan a UPC code of product like Wii game console, the UPC code is used to match ads of similar products like PlayStation game console or Just Dance DVD game.
Simple and intuitive, right? And there is more. Based on CDIAA, you can apply existing technologies like geo-location targeting, user profile targeting and cross device targeting to achieve more relevancy.
Content-Driven In-App Advertising is a patent-pending new technology. You can find more here.