Craigslist is great for SEO purposes. The ads actually produce results too! Post a simple ad for your website, but avoid the “for sale” section. It is heavily policed and you’ll get caught very quickly. I post my ad in San Francisco, Los Angeles, Chicago, New York, Miami, and Dallas. These are the most populated Craigslist sites. I post every 7 days with an ad that includes my URL. It generates traffic and can get your site indexed by the search engines within a few days. The backlinks it creates are very powerful, as well.

Ebay is a link building tool that must be handled carefully. They do not want you linking to your websites in most spots. There are a few instances where you can get away with it. Your “ME” page is one spot you can use to link to your websites. Another method is to link to your website in an auction to a “non-sales” manner. For instance, you can post a link to a page of images for a product. You type – click
here for more images and make it link to the page on your site. I recommend setting up a store there, as auctions only last a week. Store listings last at least 30 days.
Ebay offers a bunch of features to direct traffic from within their site to your listings and profile. They have a wiki, blogs, forums, and chat rooms. Use these! Post articles to their wiki, blog using their service, chat in the forums and chat
rooms. Brand yourself on Ebay and your business will benefit greatly.