Craigslist is to hookers what Walmart is to produce. There can be much more to the shopping experience.
The internet excels at the free flow of information. If you like to build cars and talk with others that like to build cars, there is a forum for you. If you like to dress up your RealDoll and take it on dates, there is a forum for you.
If you want to bang your local hookers, want to know how to find them and which ones are the best or will let you do the most depraved things to them, there is a forum for you.