You can 'invest' if you like. Just copy the links into your address bar. Yes, I will get a percentage of your investment for getting you to sign up & invest.
The trick is to play until you get your money back with enough to reinvest back into the program. Then play with the money earned, pulling a little bit out at a time. That way, you lessen your chances of losing your money. Only use money you can throw away.
Just think of it like placing all your money on black at the roulette table. You might double your money or lose it all.
Don't forget to claim any and all earnings for your taxes (if required).
Most require an e-gold account to play. Others Stormpay and EMO. There have been some issues with stormpay...so I would suggest opening an EMO account and use that to fund your e-gold account.