After email, chat is the most popular online past-time. Or check with your site host.
Chances are they offer a chat room package for a nominal fee.
Follow that Thread Threaded message forums no longer have to be a CGI nightmare. Many Web hosts provide message applications. There are also applications written in ASP, Java and ColdFusion which are completely customizable by the licensed owner. Create a few key topic areas, recruit a friend or two to help monitor the activity and clean out the dead conversations and presto, you have an instant traffic source as people read and write messages day after day. As long as your user policies are clear and concise and enforced, classifieds are a valuable user service that can provide you with a measurable return on your investment.