I was in the payment portion of posting an ad. When I submitted it, it said my card number was wrong. I checked the number on the card and on the screen. They matched. Everything matched. I submitted again. Not only did it charge me a second time, but it still didn't post my ad. It still says my card number is wrong. Which is clearly not the case because I was charged 2 $5 fees in a row on that card. User's recommendation: I have no idea. Don't use Craigslist to post an ad?