Yesterday I wrote about InMobi’s bold plan to grab mobile advertising market share while the getting is good. Apple and Google are distracted in an ugly turf war over iPhone/iPad advertising; meanwhile, InMobi, one of the largest international mobile advertising networks and backed with U.S. venture capital, is just starting to make inroads into the U.S. They soft launched in the U.S. earlier this year, and turned things on formally a couple of weeks ago.

Today they’re announcing a $2 million world developer fund to encourage application developers to use InMobi for in-app advertising. Developers on Android, iPhone and iPad are eligible.

Here’s how it works: first come first serve. Sign up for the program and add InMobi via their SDKs. InMobi usually keeps 40% of gross advertising revenue, and 60% goes to the developer. But during this program developers get to keep 100% of the advertising revenue, and InMobi’s 40% comes out from the $2 million. Once that $2 million is gone the normal split applies. See this video for more details.

This clearly encourages big names to sign up because they can grab a chunk of that $2 million fast. Of course total revenue depends on how much InMobi ads are selling for. If developers have feedback on their monetization rates v. AdMob and other ad networks, I’d love to hear it in the comments.