Boy, you really nailed it.

I hardly look at these offers any more. They may be OK if you are booking (not upgrading) in First or full-fare economy. But, who does that anymore?

Reminds me of the car and hotel upgrade coupons that keep coming. These terrific offers can generally be had by walking up to the counter and asking - or bettered by a little shopping on line. So I throw them away as they come in.