Hi, Mark! (7th comment)
Trench is not bad... I mean, back when he started his blog I was glad someone else was taking a critical view of craigslist and keeping it up but I don't find his analysis particularly insightful.
Here are a couple of people I found worth reading and quoting on the subject of craigslist prostitution: Connecticut Attorney General Richard Blumenthal (the existence of craigslist's erotic services "increases traffic and generates a number of users [to the site], which in turn enhances their revenue);" Steve Diamond, business law professor at Santa Clara University ("Newmark and Buckmaster are driven mostly by self-interest") and University of B.C. associate law Prof. Janine Benedet ("there is an argument they are really sort of pimping").