Pretty crazy, they jumped on it already, I pictures here of YPN Randomizing Number of Ads, like Google AdSense just announced they did.
Looks like a simple case of "monkey see, monkey do". lol Maybe there is something to randomizing the number of ads. The question is, is this more for the SE or for the users?
hum yahoo can create a big alternative to adsense coz they already sell tones of things on their website so they have lots of advertisers