i did the Arb betting. Put £200 in an account, used a site to get the bets - by the time the money clears - you can do maybe 3 bets in 2 weeks at around 1-2% a time. Using the free bets I quite quickly got up to around £800 (almost all using the offers) was a bit weird betting on 2nd division Romanian Basketball games but was fairly straight forward. Once I was at around £800 I bet on a tennis match in which someone got injured after 1 set. The 2 sites had different rules & one bet went to the winner & one to who was winning - sods law I lost both rather than won both as the person who was winning retired injured. So a) check small print & b) as someone said, if it was that easy at a bigger scale - you can imagine that someone would be doing it, on this scale or even there would be an 'Arb' Investment Fund. Worth doing for a quick £500 if you have the discipline to set up the accounts but I think the technology is fairly sophsiticated & even if not, a bet of £473.59 on Bucharest B would look unusual! & i think bookies can spot it & void a bet fairly easily.