A brief History of Progressive SlotsIn the beginning there were no such thing as progressive slots; they only became possible in the early 1980’s when microchips were added to slots machines. Even then it wasn’t until March of 1986 that the first multi site linked progressive slot machines were introduced by the slot machine manufacturer IGT.Having the same jackpot being fed from a number of different machines (which are often spread across a number of different casinos) means these progressive jackpots can quickly grow to be very large indeed. I have heard of casinos in Las Vegas where slots players have won over $8 million in a single win on a progressive jackpot.How Progressive Jackpots WorkProgressive Jackpots grow by skimming an amount of money from each and every bet; this means that their payout rate on normal wins (non jackpot wins) is lower than that of a regular slots machine. However if you take the progressive jackpot into account the payout would be the same.For example if you were playing at a Las Vegas casino on a linked progressive slots machine with a fixed $5 bet per spin. Your money could be divided as follows, 25 cents adds to the progressive jackpot, $1.25 goes to the casino and the remaining $3.50 is paid out in non jackpot wins. If however you were playing a non progressive slots game at that same casino it is likely that your money would be divided as follows. $1.25 to the casino and $3.75 paid out on wins.The example above assumes the casino has a 75% payout rate, in reality slots at land based casinos typically have payout rates ranging from 70% up to 87%. This is in stark contrast to the online casinos which typically have payout rates from 89% up to as much as 99.5%!So at a typical online casino with a 95% pay out rate the money you pay in for a $5 per spin online progressive jackpot slots would be divided up something like this. $0.25 for the online casino, $0.25 added to the progressive jackpot and the remaining $4.50 is paid out in non jackpot winnings.Given these statistics it is not hard to see why many hard core slots players are now playing online from their computers.Online Progressive Jackpot gamesSo apart from the free drinks playing online sounds more favourable as a player (in that you should win more). However I have already said how large jackpots can be at land based casinos so your next question is no doubt going to be just how large are progressive jackpots at online casinos? The answer to that is that they are growing all the time, the current record is $1.76 million and interestingly the exact same slot machine that paid that out in December 2005 currently has a Jackpot of over $3.5 Million and still rising! The slots game in question is millionaires club progressive jackpot slot and when this jackpot is eventually won it is going to set a new record for being the highest progressive slots jackpot of any online casino to date.I have no doubt that even after that has been won a new record will be set within a space of less than a year, the rate at which progressive jackpots online are growing is amazing, only a couple of years ago a jackpot of a little over $1 million held the record. It is my opinion that sometime within the next couple of years the highest jackpots will be being paid out from the online casinos.So how do you pick a winner?Choosing which progressive jackpot to play is really not all that complicated. Once you know what the progressive jackpot starts at, what its highest payout was and what its average payout amount is. There are a number of slots sites that give you this information including the any of the progressive jackpot reviews at slotsjam.com.Obviously once the jackpot in question is higher that it’s historical average the chances of it paying out are greatly increased, and if it goes higher than its previous highest payout your chances are further increased again. So if you are chasing the biggest jackpots don’t play the games just after the jackpot has been won instead wait until after that games historical average payout has been passed for the best chance of winning big.