One thing that’s interested me is the concept of matched betting - basically you place a bet for a certain result with bookies and against that result (lay bet) somewhere else. The way you make money from this is to, with the aid of some simple maths, use free bets that bookies award all the time on the lay bet, and you’re always guaranteed a profit. From what I’ve heard though, to make any proper money you almost need to treat it as a full-time job.