First, and possibly most importantly, Sunday is free popcorn day at AMC theaters. And they're going all out: You get a large! Very exciting stuff.
Second, they're updating their Stubs rewards program. I never liked a program where you had to pay to join, but the discounts were worth it. Now, there's a free version and a paid version. If you had been in the previous program, they'll automatically move you to the paid version of this one. Here's how the chart breaks out. The biggest benefits to the paid program are the waived ticketing fees, 10% rewards (versus 2% in the free program) and free popcorn/soda upgrades.