The latest bulletin board to host erotic and sensual massage classified is the infamous Craig's List. Craigs List started in San Francisco, but has since expanded to cover most major cities.
It is still considered very risky to seek out adult services from anonymous online classified systems like Craigs List, but more and more of the discussions on the hobbyist boards involve experiments with providers found through Craig's List.
Most I have seen so far express disappointment, and some reveal true risk of scam, ripoff, and other trouble. Sometimes you see a poster talk about a wonderful GFE or something unbelievable, but not usually.
I think that Craig's list may be strong entertainment for the true thrill seeker, but not a main venue for the adult sensual massage enthusiast.
