AdMob, one of the biggest mobile ad networks, is working with application developers to build ads customized for iPhone apps.

The startup company is giving away $1 million in $5,000 chunks to developers who come up with the coolest ads that take advantage of iPhone features like music, maps or video, and go beyond the text and static image ads that make up the bulk of AdMob's inventory. 

We caught up with Admob CEO Omar Hamoui at the MobileBeat conference to get some details on the program.

The main takeaway was how much AdMob is making from iPhone users. The ad network gets at least $30 CPMs for branded ads, more than three times the $10 CPM minimum it gets on average.

That's good money, especially when you consider that the company served up 3.5 billion ad impressions last month, more than 10 times the number of a year ago.

While he wouldn't give specific figures, Hamoui said that revenue is growing at a similar rate.