Matched betting (also known as back or lay bet matching, or double betting) is a betting technique used by individuals to profit from the free bets and incentives offered by bookmakers. It is generally considered risk-free as it is based on the application of a mathematical equation rather than chance. A typical return for a matched bet where the stake is returned is 85%+ of the free bet offer amount, and 70%+ where the stake is not returned. Most free bets are stake not returned. (Full Wikipedia article)
Place bets with two bookmakers on opposing outcomes. One or more of the bookmakers must be offering freebets or other incentives. The bets cancel each other out, no money is lost, and the freebets or incentives are kept by the bettor. Tax free (in the UK).
I have done something very similar to bonus bagging, years ago when I started out in this game (I made a killing). I had a mentor (Hi Rich) who I’m still in touch with. In fact I’m currently (November 2016) working with him again. It’s a bit different this time, as I already have accounts with most bookies… (he makes his cash from affiliate commissions)
Apart from that, I am currently reviewing MatchedBets.Com, and will be posting my results as soon as I can.