If you are purchasing premium cabin flights, the IAP program that Wyfind posted about above can be a great benefit.

I have saved enough money on just 1 purchase to recoup the AF, and made several others that were significant cost savings. This is real savings, as compared with both direct bookings with that airline as well as google flights, etc.
It also sometimes has reasonable one-way fares when other options are much more expensive.

I was skeptical that this was a true cost saving possibility, but have been impressed.