This sounds better then it actually is, you're getting .018 pp but loosing out on .015 (Amex Everyday) on your next Amazon purchase which is worth more,
Except if you have a lot of extra UA laying around.
Don't know what you're talking about.
Are you actually saying that using gift cards for my next $100 order where I lose out on 150 MR makes this not such a great deal?
This is an awesome deal, I think you are a bit confused.
This is only a bad deal if you have your business class tickets waiting to be booked, and you get a GC instead.