Turns out Wikipedia is one of the top ten most visited sites on the web according to Danny Sullivan:

1. Yahoo Sites, 129 million
2. Time Warner Network, 117 million
3. Microsoft Sites, 115 million
4. Google Sites, 113 million
5. eBay, 81 million
6. Fox Interactive Media, 75 million
7. Amazon Sites, 51 million
8. Ask Network, 49 million
9. Wikipedia Sites, 43 million
10. New York Times Digital, 40 million