I have bet probably 3 futures in the last 2 years - one on an NBA series, one on an NHL series, and the final one on the Cubs to win the WS.
All were taken with the specific purpose to cash out on what I considered to be very overly generous odds. The NHL bet I lost, it was never hedgeable, the other 2 I cashed extremely well on by hedging, and interestingly enough, both of the futures bets actually lost outright.
Admittedly, relatively few gamblers enter into futures bet with the plan to hedge beforehand, so I understand Pat's point to a degree, especially a gambler who is CONSTANTLY making and losing futures bets - for such a gambler, his overall picture of losses from prior futures bets probably gives him an incentive to let it ride, otherwise he'll never realize the profits that will (hopefully) more than cover his past losses.
Another point I made earlier was about injuries - let's say hypothetically that you bet $1,000 on the Celtics to win $40,000 if they won the NBA championship this year. And they had an amazing run, and managed to get into the championship series (but don't have the home court advantage), except you find out 1 day prior to the first game that 1 of the starters pulled a hamstring in practice and 3 others are ill with a pretty bad flu. Obviously I'm exaggerating to make a point - here, a rational, intelligent non-degenerate gambler would hedge like a mofo. Point being, you have to consider the situation.
Here's another example of a hedge I did last night - when I thought Enrique Wilson would lead-off, I put some coin on him to score the first run and a little on Juan Pierre as a hedge. But late, I found out that hot-hitting Jeter would be leading off, so I hedged on him again. In other words, I hedged due to changing information. Result - I cashed half a unit, but more importantly I avoided losing.
Different types of hedging for different reasons.