I see that as opportunity. You could be the startup that moves roommate search/matching online in Turkey.
In Germany about 18 months ago two startups started heavily promoting in Facebook. Students are looking for apartments, there are (often open or easy to subscribe) Facebook groups for each city and university and the startups posted apartments there. "Look here somebody is looking for a roommate". I hated the ads but people remembered and use them now. It worked.
Even paper ads on blackboard at universities work. Calling people and offer to post their (paper) ad for free online works. Not scalable, but viral growth needs to start somewhere. With that in mind read http://paulgraham.com/ds.html again.
With classifieds the number of listings often wins. Craiglists looks bad, ebay was user interface disaster for the first couple of years. But everybody goes where the most listings are.
One monetization method is micro-payment. Users have to send a SMS with a code to see the renter's phone number or similar. Or buy tokens. Or listing creators can pay to get promoted (check out http://www.gumtree.com/, you can buy that your ads remains on top for a certain amount of time, I think http://slando.com/ does the same).
