In short....the MagicBands make being in Disney MUCH easier.
I linked my debit card to it and that's how I paid for the snacks or souvenirs we purchased in the parks. It was nice to know I could leave my debit cards someplace safe and not have to bring it into the parks daily! Not having to keep up with the tickets was a blessing! All I had to do was look down at everyone's wrist. Is there a band on it? Then we're good to go!