There's gambling on backgammon in the same way there's gambling on chess (or any game): sure, you can play for money, but that's not really the usual way to do it. Nothing in the game requires it. Backgammon clubs work essentially like chess clubs.
And no, the doubling cube does not make it similar to poker. The doubling cube is just a way to add another element of risk/reward to the game. In poker, you literally have (fake or real) money in front of you and the entire point of the game is moving that money into the pot and trying to win the pot to gain more money. There's nothing comparable in backgammon.
