The pair operated the Punters Club, an Australian betting syndicate which traded Billions of dollars each year. What they did was build a sports modelling software which traded between different platforms, not unlike a arbitrage software. In fact, their was more to it than just identifying inefficiencies in betting odds, because these guys also negotiated rebates. 

Maybe you know this already, but for those who don’t their are many commission agents in the bookmaking industry. Examples of this are betting platforms which feed Pari mutual pools, such has you find with Australian, US, Hong Kong and French racing. To get bets into the pool, PMU operators offer a turnover commission to betting agents. In fact, with the HJKC anyone losing a total amount of HK$10,000 (US$1080) or above is eligible for a10% rebate. The main aim is to stop people betting on the Black Market. 

We should also point out Football betting agents send billions (dollars) in bets to Asian handicap bookmakers every month. The likes of Pinnacle sport, IBC, Singbet and a number of others work with agents, and in return they either pay a commission on stakes (around 0.1 to 0.4%) or share the profit/risk. Commissions are much lower in football since the average bookmaker juice for a top leagues is round 1.5 to 2.00%. This usually translates to the bookmakers win being about 1% of the total take. 

What the Punters Club used to do was offer offer the best Asian odds to customers using Betting exchanges, and for this they would receive a two sided commission. The first part was  from the bookmaker has previously mentioned, and the other was a share of the betting exchange’s commission. Without the likes of the Punters Club, betting exchanges like Betfair wouldn’t have been able to generate adequate  liquidity. 

Their was also others doing the market making for betting exchanges, with Swedish owned Bettingpromotions springing to mind. And, these companies were not limited to working with just exchanges, because their software would also look for arbitrage opportunities within the bookmaking community.