Self-managed rich ad platform for iOS apps?

A media publishing company has an existing inventory of advertisers for their traditional media channels. Their iPad app is doing very well, and they want to use their inventory for in-app rich advertising.

I can't find any rich ad solutions that allow self-management. AdMob is the closest so far, but it's not true rich media: http://www.admob.com/marketing/ivau

I read some vague references to Medialets partners, but nothing concrete. Can someone please recommend a platform/provider who can deliver this?

(To cast this in programming terms, I need an ad provider who offers an iOS library/API serving ads in HTML5 or similar, and lets me upload my own 开发者_开发百科content).

Medialets contacted me, they offer self-management for a fee per click. It's pretty expensive but I can't find anyone else who does it.

AdMob seems to allow free self-management but only for traditional ads.