From the house edge calculation point, the statistic probability of making money on slots is much bigger than the same way calculated making money probability for Blackjack or Baccarat. The slots usually have the 6%-8% house edge(AFAIK), so it is logical to expect the huge promotional demand by the casino management in order to lure the majority of site visitors. The welcome bonus offered free spins and huge wagering requirements is directly connected to this purpose, so don't waste your time convincing gamblers to prefer dice over slots.