Craig's List shut off its "adult services" section a while ago, amid loads of complaints that it was basically a prostitution marketplace. There was a belief at the time that the, uh, merchants would simply gravitate to other sections of Craig's List, like massage therapy or something. Turns out, however, that everything just moved over to Facebook where it's easy to set up a page, let people send you messages, post pictures. All this according to a Columbia professor publishing his work at Wired. What's really interesting, however, is that the migration to Facebook started taking place BEFORE Craig's List made changes. Facebook is just a better channel for prostitutes.

Of the women I talked to, 61 percent said they've used craigslist, mostly for advertising. But even before the crackdown on the site's adult-services section, sex workers were turning to Facebook: 83 percent have a Facebook page, and I estimate that by the end of 2011, Facebook will be the leading on-line recruitment space.