How long until somebody hits the jackpot? That's what people were asking themselves when Mega Moolah went past €6m not too long ago. No comparable game makes comparable wins possible, and hardly any other kind of game is as popular as the progressive jackpot. There's a very simple reason: These games are part of a huge system that's played by hundreds of thousands of people every day, and every real-money wager placed on a progressive adds to the winning sum.

Usually sites feature anywhere from a few to up to about 20 of them, still a relatively small percentage compared with often hundreds of slots offered by a single online casino. Anything else would go against the general idea here: The more people play a single progressive game, the more attractive it gets to others. This section's where we introduce and review the best.

Although popular, a progressive jackpot is still as hard to win as any slot. Usually, the only combination that triggers the jackpot is the one with the highest payoff. The amount of every bet that goes into the jackpot could for example be 1% at a house advantage of 5%. That means that the house (the casino) is happy to contribute a fifth of their profits to the winning sum. They do that because the progressives drive visitor numbers. A fast-growing game that always comes with a nice total win attracts a lot of players.

Another point is that once the progressive is won, a percentage of it stays in the pot and makes the basis of the jackpot of the next round. This is called reseeding. The idea is to make the jackpot immediately attractive to players again and start off the next round as quickly and smoothly as possible. As soon as the popularity of the game grows again, so does the winning sum. One factor drives the other, the jackpot increases until it's won, and the circle begins again.

Progressive jackpots have been around for quite a while now and are still exceedingly popular. Some of the greats include the mentioned Mega Moolah and other similar games, like Mega Fortune, Mega Joker and many others.