So, how does this work?
Let´s say Coral give us £20 free bet. If we place this on Manchester United to win, Coral might give us £20 as winnings however if Manchester United draw or lose we won’t lose anything as they gave us the £20 free bet to bet with but we wouldn´t win anything either.
To even things up to be sure we make a profit regardless we use something called a betting exchange and the most popular is Betfair. A betting exchange allows us to take a bet, known as laying. If we layed Manchester United for £10, if Manchester United won we would pay somebody £10, meaning a £10 loss. But if Manchester United drew or loss we would keep the £10, meaning a £10 profit.
Now if we put these two bets together
If Manchester United won, we would win £20 with Coral, but lose £10 at the betting exchange, leaving us with a £10 profit. Now if Manchester United drew or lost , we would win £10 on the betting exchange but lose nothing at the bookmaker because it was free bonus money we were betting with.
Now there are literally hundreds of sign up offers from bookmakers that you can complete in this way and there are daily offers know as reload bonuses from betting sites to keep you betting you can keep repeating this process to make guaranteed profits day after day