You already know that you can play the games from one software provider across a number of casinos. If you play a progressive jackpot game which is pooled over the entire network of casinos which the provider powers, you will see that the jackpot prize is the same at every casino and constantly rising. This is so because every bet that is made on the game from all players, across all casinos which have the game in their offer, contributes to the top jackpot prize. This is how some progressive jackpot slots like Mega Moolah or Mega Fortune can reach over $15 million.