Agreed. My argument was perhaps a little strong. Craigslist is far from a monopoly and people can and do successfully list their apartments in all sorts of places.

I do think there are web companies who could really do some anti-competitive things that we should watch out for. Facebook is probably the most capable, or maybe Google if they went off the deep end and started holding companies hostage through their search. The argument still stands, I think, even if it doesn't justify intervening on behalf of a company that wants to improve Craigslist search.