Social media marketing became really popular over the last 24 months and a lot of "experts" explore traffic from Digg, Myspace, Facebook and all the other great Web 2.0 networks. Usually most experts get caught by spam filters, algorithms or hand-editing after a while, and the screaming after the storm is usually immense. Especially when it used to be a great and easy revenue stream. What most of these experts forget is that there is a large online savy Ebay crowd, that still can be easily explored. E.g. 14.5% of the overall internet usage is spent on Ebay in Germany (unfortunately couldn't find numbers for the US, but I doubt that it is below 5%).
Unlike other social networks , the Ebay crowd is also not just "hanging out" for fun, but most probably have the intention to buy a product.
What can be better than having millions of people waiting in a mall and ready to buy pretty much anything?
I still explore the Ebay crowd for some of my sites with great results. It's one of the easiest and cheapest ways to receive quality traffic. Especially when you can use Ebay tracking solutions like Infopia.