I remember learning that that in General Biology when I was in college. It kind of surprised me, but it's a fun fact to share with people that don't know. I think there was a guy who wrote a book about this, or at least as part of the marketing of his book.
Didn't Dennis Miller do like long distance telephone call commercial, with the pitch line, of you can't buy anything for a dollar.
A dollar is a pretty fucking good deal for all the porn your dick can handle for a day or two. Especially since Hustler has videos like Who's Nail'n Palin?