I’d run from this one. Way overpriced IMO. I think they (FB management) recognized the fad was ending and cashed out. I believe it is in a fast fade. Be lucky to be $10 by end of 2012.
They can’t push ads to mobile yet and plugins like Adblock effectively block adds in browsers (although the impression may still count.) They also face tremendous infrastructure challenges.
They do. Impression revenue is earned when the page is served, whether it's displayed or not.