@Erik: Unfortunately there aren’t a lot of options for apps looking to make money with advertising on MySpace at this point. Cubics.com has been working on the MySpace platform since it officially went live. We're owned by Adknowledge with sales teams on 3 different continents including a dedicated brand sales team here in the US and they're working to sell inventory across all of the SNS that allow it.
If you look at the most installed apps on MySpace, they're all basically from the same players: Slide, Zynga, RockYou, etc. We all know that MySpace has been stingy with allowing growth and we all know they've had growing pains. So I don't expect that any of the major players are focusing much attention on this area beyond capturing market share.
One developer I spoke with had similar issues working on Hi5. For quite some time, they didn't run ads on that platform because it just wasn't ready to go. They felt that putting ads on a flaky app was just adding insult to injury. This was two months ago.
Trust me, we're here and ready to help you monetize, but from the feedback I'm getting, it's a platform issue.