Remember those underground casinos you seen in the movies? The internet has them too! Not only are they playable, but they are in 3-D. The internet allows for this kind of "business" and allows the person running the game to avoid taxes. Currency like Bitcoin brings an added-value to selling the casino games because it allows the players and the owners to operate under anonymous screen names. Will this be the new revolution of online business? With internet sales tax it -- maybe.
The trill of playing poker with the Las Vegas ambient lights of a casino embedded in the underground private browser window is enough to get young adults ready to cash in money. Interesting thing is I wouldn't be surprised if this underground casinos start allowing real life money or money from online games -- Runescape Gold.
Where there is a market there is a profit and the internet is just digital data which keeps transforming things into opportunities! There is already an open currency market for things like RuneScape Gold, SpaceBucks or other strangely labelled global virtual currency out there that allows the particular virtual world's players to purchase in-world items.