

They provide entertainment, generate tax revenue and keep people employed (although, if exchanges didn't exist, people would probably spend the disposable income they put into the exchanges on other products and services that do the same).
They also act as a regressive wealth redistribution mechanism, with the lion's share of the profits probably going to wealthy traders and bettors (and if the clients of your typical bookmaking establishment are anything to go by, it will primarily be people on low to average incomes who are at the bottom of the ecosystem). As richer people have a lower propensity to spend, that may mean more money being sat in people's bank accounts, rather than stimulating the economy.
Jeff
BabyArber wrote: What value do betting exchanges provide for society?