super70s - 10:30 pm on Sep 22, 2011 (gmt 0)
I set up an ad with them about a year ago but never activated it. They kept sending me $50 credit offers so a couple of weeks ago I finally relented. The credit was used up in about 10 hours and they were into my credit card for $8 before I could pause the ad the next morning. Maybe that's what they're after -- people who don't realize how quickly a $50 credit can get used up.
If they send me another free credit offer I'll probably take advantage of it but this time I'll set the daily limit to a lot lower than $50 and/or not activate the ad right before I go to bed. :)