Originally Posted by
trapped
Wow, this thread blew up quickly since I last checked it this AM. I thought I'd submit an interesting data point. I booked two one way fares from LAX-LHR, both were purchased for $635. I then went in to manage my reservations to add my Delta FF# to each ticket. One of the tickets estimates that I'll earn 21,339 miles while the other estimates that I'll only earn 3,494 miles. Both fares appeared to be the same at the time of booking so I'm not sure what's driving the difference. Just thought I'd throw that out there to see if anyone else is having a similar experience.
Those are the FB earning rates, and FB goes revenue based (4 miles per € up to 8 miles per € depending on status) effective 1 April 2018.
One of your tickets is entirely before this date (and so earns at a 300% basis on distance travelled), while the other is based solely on the price paid.
As already noted upthread!