I have been working with inneractive and Vserv for in-app ads, and I was relatively satisfied, until recently there was a huge drop in inneractive's performance. Since this isn't the first time inneractive has caused me grief, I decided to switch to another ad provider.
Only problem is, I don't know any other ad providers that have a solution for J2me.
What about you guys? Is there another ad provider you have had experience with?