An interesting approach might have been adwords for apps. Apple came out with "get users comfortable paying for apps & take a 30% cut" model which suits them a

An interesting approach might have been adwords for apps. Apple came out with "get users comfortable paying for apps & take a 30% cut" model which suits them as a company. But, realistically a lot of apps don't make their money from directly selling the app. A lot of apps might be willing to bid against each other for users. I'm not sure how big a market this is but it could be substantial.