profitability. go Google Adsense.
others. go Adbrite.

Adbrite works better in forums but not in blogs. Nuffnang is even more awful, the advertisements are shown if Nuffnang likes your blog, or else you are just helping Nuffnang to promote in your blog without charges. Maybe you can get more advertisements from Nuffnang if you put some lovely photos of yours haha.