Odds are high on the slots, but not good for the player. Expected return on most slots is 95% or less. But yes, for a small number of plays, you could turn your $25 into several hundered; it's just not likely. If you're going to play the slots at TI anyway, this is a good deal, as you can put $25 of your dollars back into your wallet and use their free play. Promo chips are the same thing. I don't know this particular promo but normally in Las Vegas you can play a promo chip until you lose it, so it's just like a live chip that you can't cash.