More sites like Craigslist? Marketing paintings.?

I need to market discounted large format original paintings and don't want to fight it out with Art.com and others for search engine placement. I'm looking at puting up a website and advertising it on other sites like Craigslist.com. If you know of any other sites like craigslist or have any other ideas on how to market this product I would appreciate any advice you care to share.