I guess a way of asking is why are we so married to the concept of classifieds. Maybe you should look at innovation in finding jobs, finding houses, etc.

Ebay is an innovation in buying selling stuff (once classifieds territory).

Personally, I think maps/real-estate, very possibly from Google could be a major point of attack. just makes sense to find real estate on a map. Also makes sense to book hotels. 2 money areas online.