Here, in case you're wondering, is how the World Series proceeds are distributed to the players.
Here is how it worked out in previous years:
World Series Gate Receipts and World Series Player Shares
It's important to note the main point, that there is no incentive to stretch the series beyond the 4th game, because only the gate from the first four is counted into the players' share.
A few interesting notes. In 1903, each winning player got 1.2c per ticket sold. In 2009, it was $1.26 per ticket sold. Almost exactly 100 times as much.
Before divisional play, the purse was distributed down to the fourth-place team in each league. In 1954, the Red Sox finished 16 games beolw the .500 mark, 42 games out of first place, and got a WS share. The Tigers finished one game behind them, in fifth place, and got nothing. That was significant in those days, when many veteran regulars were paid less than $100 a game during the regular season. There was once a team (I forgot which one) that had a rain out that was not made up, and finished a half-game out of 4th, and lost their share as a result.
In 1981, Dave Winfield was accused of slacking in the WS. His regular contract called for $8,000 per game, and the difference between the winners and losers share in the WS was only $10,000, so he would gain a lot less per game by winning the series, than he made during regular season play.
There could, I suppose, be a financial incentive for a second place finisher to play their final games such that a team with a bigger stadium would go to the post-season, thus proving a potentially bigger gate to be divided among the players.