This piece is from 2007, so I wonder if this is still true.
It’s no wonder that Craigslist is champion of the online classifieds revolution… Analysis of eight major American cities shows erotic services consistently garners the highest number of individual visitors for February — almost always twice as many as the next ranking category, averaging 265,000 people per city. Equally racy lists that consistently score high visitor volume are the section for casual encounters as well as personals for women seeking men. The most commonly frequented venue outside of this virtual red-light district? Cars for sale.
(via compete pulse)