Its been banned by google, many companies promoting these offers are being investigated by the government. http://www.shoemoney.com/2007/11/12/azoogleads-gives-1-million-dollars-to-florida-ag/

On limited inventory it pays 20 times as much as google adsense.

Its definately interesting numbers but the real test will come to see how much they make from non cell phone revenue and revenue that doesn’t come from selling installations to other apps.

At the end of the day making money is all that is important and it looks like they are making cash, the real question is what is a facebook user worth and how sustainable is it. Slide.com funding is another thing to look at.