One of the other forums Im on tried using an out of forum classified engine. You had to enter the classifieds from a button on the top (like up where it says Decals, Calendar, etc) and then go thru the classifieds folders that way.
It was an absolute failure.
Most people just click on the Buy/Sell link IN FORUM to browse just like they do with General Discussion, Product Reviews, etc.
Having a complex Buy/Sell engine that isnt absolutely 100% easily accessable drives away browsing.
actually ive been a member on several forums ranging from a couple hundred to +50,000 members that have tried to do a classified system that isnt forum based. every one failed, and they went back to the regular in forum system