In my case, what's mostly disappeared (other than Big Win Fall 2013) is completed ones. I have an uncompleted (not sure what the terms of it were, and I'm sure I'll never complete it in the next 4 days!) Book Direct 2013 that's still showing.

At any rate, remember: A promo code showing in there does not mean it will ever pay out (sometimes they have terms you don't know about or restrictions you don't know about), and a promo code that's not showing can still pay out. So the online My Offers promo list is just there to make those who don't know how it works feel good (or bad), it means little more than that.