Here's how it works in a nutshell...
The site gives you $0.10 (real money) to start betting with. You can bet on almost every sport: MLB, NCAA, NFL, NBA, NASCAR, soccer, tennis and more. You can bet on the spread, moneyline, over/unders and parlays. Payouts are based on the odds. If you lose your bet, no problem...the site gives you another $0.10 to start with (again and again). You have to win a minimum of $20 to cash out.
The site is great to test out your sports betting skills without using your own money.