Baseball-Reference is an amazing site. I use it daily to check stats and numbers on any player that I want. Even if he only played one season in the minor leagues in 1980, B-R is pretty much guaranteed to have his stats.
On each players page, B-R allows fans or websites to "sponsor" the page. It helps them wrangle with server costs and whatnot.
Well Johan Santana's page has a bit of "internet graffiti" on it.