I've used it to keep track of balances, but the only real reason I use it is to liquidate BBrewards points. I rarely if ever shop there, so its nice to get an extra .5miles per $ spent there.

BBRewards gives 1 point per $1. Sure I can convert these back to 2% cash back (500 points=$10), but I never shop at BB, and also this purchase was below that threshold (netted 450 points), so I'd end up with $5 to spend at BBuy, which expires in 90 days, and 200 orphaned points or I'd have an orphaned 450 points.

Points.com got me an extra 220 US Air miles for the 450 points. Not a great value, but helps to make the overall purchase that much sweeter. Was a purchase for a friend so the miles were all "free" in essence.