What’s the most effective way(s) to trigger word of mouth in a town to promote a classifieds site? I’d like the word to spread like wildfire. I’ve told a few friends but that’s not enough.

I’m trying to promote a free classifieds site in a town of 30,000 and I’m looking seriously into word of mouth marketing. I don’t think newspapers allow advertising of free online classifieds sites (they ignored my emails and never called me back) and I’m trying to spread the word by word of mouth. The site has a lot of listings already I posted and from other friends. The more answers the better. Thanks for your time.
By the way no “Put a fake body part for sale” posting please. lol. That works but that’d be the last resort.

Stephanie Leffler and Ryan Blair discuss the growth of viral websites like Social Diva and Flavor Pill. Leffler and Blair discuss how these two companies have grown and used the web and viral marketing to gain popularity and an avid following.