 Betting exchanges offer advantage players a chance to make a larger profit than possible with bookmakers because exchanges charge commission only on the net winnings in a particular betting market.One way to make money on the exchanges is "trading" - in the above example, the Jets might be a favorite decimal odds of 1.90 to defeat the Bills.If a "trader" thinks these odds too long he may bet $1000 on the Jets, and should he prove correct and the odds on the Jets get shorter, "lay off" by laying, say, a $1016 bet against the Jets at 1.87.