It's Amazon Prime Day 2: Revenge of the Prime Day. At least that's what I have written on my calendar instead of the official title of Prime Big Deal Days. It's another double-day sales event, so I think my name is OK. Just kidding. The rules for Big Deal Days are exactly the same as the proper Amazon Prime Day event from July: anyone who signs up for an Amazon Prime membership (or sign up for a 30-day free trial and cancels it immediately after, if you're clever) will be eligible for exclusive discounts. Of course, not everything listed on...