There's not enough detail and investigation in the article, but this appears to qualify as a third-party posting service, which is a no-no in Craigslistland. I don't see any other way they could offer one-click posting where the airbnb client didn't already have a Craiglist account (and not even then, either). If this is indeed what is happening, Airbnb should tread lightly lest they get the banhammer, and this is doubly true if the resulting Craiglist ads appear to be Airbnb ads, and/or the ads are posted out-of-area.