I was poking around on wikipedia today, trying to see what the traffic was like to some of the MRI pages. I found this page that has the most visited wikipedia pages broken down by month. The top few are obvious, the front page and a few different search pages, after that some current events, swine flu, Michael Jackson, The Beatles, etc. If you keep reading it quickly becomes a mix or random pages but you start noticing that many of the top pages form a common theme: sex, list of sex positions, human penis size, I could keep listing them but I think you get the picture. Looking at previous months the articles about current events changed but the sex articles were always on the list.
Wikipedia is supposed to be this fount of human knowledge. A huge encyclopedia were you can learn about nearly anything. After all of this effort to create it we find out that people would have been 90% happy with a few pages about human reproduction and some current events.
(By the way I later found this site which lists traffic for individual pages and found out the SWI page gets 400-500 hits a month.)