Their money.

I just finished reading Annie Duke's new book (I'll probably write a review of it for pokermagazine.com). She makes some comments about how much smoother her poker career has been because of backing from her brother, from Erik Seidel, and other's she doesn't mention.

Playing on other peoples money really does give you a strong edge becuase you can build a bankroll without having to face any bankroll risk. If you hit a losing streak you might lose your backer, but you don't lose any of your money.

Then I ran across a thread on rec.gambling.poker about cashing out the amount of the original buyin on an online poker site after accumulating a win. The person suggesting that liked the idea not because he needed the money, but because he liked the idea of "playing on their money".

Sigh.

Once you've won the money, it's your money. It isn't their money. Playing on borrowed money is playing on their money. Playing on won money is playing your own money.