I didn't like Scribd the first time I saw it, but it's starting to grow on me. The recommendation engine not only works but is brilliant, and I love the fact that I can download whole eBooks for free. My only gripe is the site design.<p>A quick look at the National Adult Literacy Survey shows the potential market is smaller than that of YouTube, but in some ways the stickiness of the eyeballs you do have is more important than the total eyeballs.