Starbucks app question

I'm just wondering how this is possible. I downloaded the passbook update to the Starbucks app but afterwards I was having problems so I deleted the app and then redownloaded it. When I opened it up I was expecting to have to log in again, but all my account information and my Starbucks card info was there. For every other app I've used I always have to reenter my information. As far as I know the app doesn't sync to iCloud. What am I missing?