Over the years technology has played a role in making the offerings ever more inventive.

Yet until recently the entertainment corporations which run the Vegas casinos had been reluctant to embrace the clicks-and-mortar world of internet gaming.

"Many operators here aren't used to the challenges of being an online company," said Anthony Cabot, a lawyer specialising in gambling legislation.

"The second major challenge is obviously legal. Unfortunately the position of the Department of Justice is that all gambling by US companies from the US is illegal."