A gaming system includes a plurality of linked gaming machines and a controller coupled to the gaming machines. The gaming machines are used for playing one or more wagering games having a plurality of symbols that indicate a randomly selected outcome. Each gaming machine includes at least one wager-input device for receiving a first type of wager, which allows the player to play the wagering game, and the second type of wager, which allows the player to be eligible for a progressive jackpot. The controller determines a first cumulative value of the first type of wagers, a second cumulative value of the second type of wagers, and a distributable wager pool that is derived from a portion of the first cumulative value and a portion of the second cumulative value. The distributable wager pool can fund the progressive jackpot.