they all do the same thing... but the bands are heavily pushed by Disney and very heavily adopted by everybody at the parks. I'm not expert, but I'd be willing to say that at least 3 out of every 5 people have them. One cool thing about the band is if you tie it to your card, on the Seven Dwarfs Mine Train ride there are no camera stops after the ride is over, but on your My Disney Experience account it will show a really cool video of you riding the ride thanks to your band and it recognizing you as you were on that ride.