There are so many pyramid and ponzi scams out there you really have to be careful. There is apparently a genuine website which tells you step by step how to use the free bets new joiners receive to UK based regulated online betting sites, and then betting on both teams winning at sports events, or both outcomes, in such a way that if you spend an entire day, following the sites instructions to the letter, you will build up a net a profit of around 1000 pounds typically. The problem is you can only do it the once, because of the free sign ups, and nowadays you are not allowed to gamble using credit, so you have to use a debit card. Go to the wrong site that is a scam, or is giving bad advice, and you could loose a lot of money. Make a single mistake and not follow the instructions exactly on a genuine site, and again you will loose a lot of money. It's not illegal, and I have not attempted it yet, but I known enough credible people who have done it successfully.