Niche Freelancer Sites?

I was considering this earlier, I’ve seen hundreds, if not thousands of these general freelancer sites, and most of them are failing - the niche is starting to fill up. 

However, what I’ve not seen many of are niche targeted job sites, for instance targeting content creation, article writing or such, and I think they would be popular. If you look on popular forums like Digitalpoint and webhostingtalk, you see a hundred or so posts a day which are after certain services, like content creation - they get huge response. Most people who end up posting on big wide niche websites are unable to find anything anywhere else, it seems to be sort of a last-call.

A niche freelancer site could be to those people what a full on freelancer site is to people with massive projects, and it could be profitable, I think. I don’t think that it should charge for membership, but if you put advertisements on it, probably CPM, then while posters are browsing looking for work, you’re earning a bit of cash - everyone wins :)

I don’t know how feasible the idea would be, and I’m experimenting with scripting to do stuff like this, but if it works out, I may launch my own.