Since the other thread I made quickly degraded into a SW spat (though I have NO understanding as to how since no mention of any other OS was made other than iOS, passbook, and the comparison of how fast retailers are adopting passbook vs NFC payments), I'm paraphrasing the entire thread.
I didn't really see any benefit of having Passbook, but the benefits are starting to be very clear now.
MLB adopted it with wide open arms, even went on record to state that they would love it if they could sell tickets exclusively through passbook. Won't be long before NFL and NBA do the same.
Starbucks, Target and Walgreens followed suit as well. All in just under a month! Won't be long before places like Wal-Mart and grocery stores start employing the use of passbook to handle electronic payments or coupon-deals.