Of all the games in a casino, there is only one that does not give the house a distinct advantage, poker. Straight poker is not played against the house; rather it is played against other gamblers, and so there is no need for a house advantage. Poker is not necessarily profitable for a casino. So why do they offer it? Well, it currently is extremely popular with mainstream America, being on a number of cable channels and its popularity is taking off. So, a casino can play off that popularity, offer it to everyone, and therefore get more people down in the casino. Of course, there's no way a casino will offer poker to people for free.