The guy made an ad that blends into reality. Who cares? There's a fat label that says it's sponsored. Is Apple evil because I watch House on television? Oh, did you notice they like to use Apple computers on that show. Glowy Apple logos everywhere. Did you see what they did there? Watch the credits. Sponsored by Apple.
Or go to CNN.com. Go to From our shows. See a show not like the rest? It's called "Advertisement" in small grey print.
This stuff isn't evil. He simply took advantage of something he could take advantage of and played by the rules. The site needs it's advertisers, and the people to keep this valuable resource of a site going for free needs it's advertisers. If the teacher's site doesn't like his product or how he represents it they can not approve the BuySellAd.
If people don't want to buy the damn Bingo software after they click the ad for it, they won't.