Depending on the pay table, the house advantage, or edge, in video poker can be quite small compared to that of other casino games. In fact, if you use an optimal strategy and with certain pay tables, you can reduce the house edge to nothing or, in fact, have an edge yourself!
That said, the payouts are usually adjusted to ensure the house has some advantage even if you play perfectly, though even then it can be as low as less than 0.5%. Double Bonus Poker, Deuces Wild and Jacks or Better are often cited as having the lowest house edge among the different video poker variations. In any case, video poker compares especially well with other casino games in which the house advantage is much higher.