I've been using Google Adsense for a while now and I think users are developing immunity to their format.
Someone recommended BuySellAds.com as provider. I submitted my site and it was sitting in "Pending approval" mode for a few days and now I can't even find a trace of it in My Account on their site. I never received any approve/decline emails... If they loose a site like that, what could happen to payoff balance?
Another suggestion I received OpenX but I think I need to instal a full-blown ad server on my site just to list my ad inventory.
There's also a bunch of those that try to wedge themselves between you and Adsense...
Is there any other platforms that are worth looking into?