The issue with this is that it appears the site is being hosted in Wilmington, DE. Since this is not a game of skill, it is almost certainly illegal to operate within that state and the states of all of those that bet from the US. Since it is illegal under state laws, the federal UIGEA (unlawful internet gaming enforcement act) also applies. It could move to a futures market model, but as it stands right now, a number of federal or state jurisdictions could press charges. I'd suggest, at least, that you move it offshore. That won't make it any more legal to take bets from US residents, but it will at least slow them down trying to track you and make it much more difficult to obtain evidence etc. If you don't want legal hassles, take it offline.