[zain]

The traffic isn't just from people following links. What about the people uploading 50,000 documents every day?

Source: Scribd says so, according to washingtonpost http://www.washingtonpost.com/wp-dyn/content/article/2008/12...

[axod]

True, although I'd guess a fair amount is webmasters trying to cross promote their content. Seems like if you own a porn site, you may as well post some "tasters" to scribd with your web address on, etc etc