Google Adsense is a game.. the one guy said it right.. the more traffic you get.. the better your results will be. That doesn't mean you should flood your page with google ads for better results.. it's probably better to have one banner ad with their text links and 10,000 visitors/day rather than have 3 text link banner ads but your visitors hate your site and you end up with only 2,000 visitors/day
I've noticed a rough estimate of approximately $1 per 1000 visitors if you monetize properly.. although I quit using Adsense (on my own, I'm not banned or anything) so I might not be the best source to listen to
By the way.. PSA stands for Public Service Announcement.. and is the same as when people refer to Charity Ads.. remember the 'Katrina Fund' ads that popped up all the time? Like that.