You have media.net which , for "some" seems to work fine. Personally, I received an invitation before they opened (some years ago), it worked great the two first week, almost the double as adsense back to that time. Then it started to crash slowly, and after a month it was near void. The more my account manager was claiming to tweak and improve things, the less it preformed. Since, I tried a couple of time without success. However, (so far) what is great, is that they are vrey reactive and it's easy to chat with them, they answer fast, but that's not what is going to pay the bill at the end of the month. However, some have good success with media.net, so you can always give it a try.

ps: we need a media.net forum, may be i missed something with could explain why it poorly performed with me.