Joining the free classifieds fray, news aggregator Topix.net has added the ability to post listings on the site for housing, jobs, private party items, services, events and "local shops." Here's the ad-entry interface and here's an example of where and how the ads appear.
This program has been going on quietly for a few months but is now gaining notice.
Marketing VP Chris Tolles told ClickZ that while the ads are merely geotargeted today they will potentially be vertically targeted as well going forward. The article also says that Topix is adding roughly 300 listings per day, which relatively good given that there isn't much visibility or promotion on the site for the offering.
Topix has other ad units that appear on local news pages. On this page the top and bottom content are contextually and locally targeted ad units. Regarding classifieds, Topix will likely be able to charge for featured listings at some future point when classifieds reach some level of "critical mass." The site may also create a "marketplace" or entry point where users can enter and search or browse classifieds directly by location.
The real news here is why aren't Topix's newspaper owners (Gannett, Tribune and, now McClatchy) doing more to leverage the distribution and community content (8,000 posts a day) that the site has built up?