Check out this website:
Basically how it works is they give you a wooping 10 cents to bet on any game you want, or do parlays. There are a couple of guys that have turned that 10 cents into over $200 so far. You are not going to retire with this money or anything, but it adds a little fun to watching the games...
My motivation for this is if you sign up, I get a 5% bonus based on what you win... it doesn't come out of your winnings its just a bonus on top of what you win. Once you sign up, you can go in there and get other people to sign up as well and then you get 5% of what they win. If you get your friends to sign up, they will all be on your friends list and you guys can compare betting winning percentages and what not.
I have gotten zero spam messages from this website, so I am certain they wont spam you... they make money from the advertising banners and such that are on the site which are pretty harmless.