Originally Posted by
gemac
If the big attraction to being Platinum vs. Gold is the 100% bonus redeemable miles vs. 25%, the calculation is pretty easy. Compare the cost of the extra flying to the cost of purchasing that many redeemable miles on AA.com. Whichever is cheaper is the least cost way to go.
Of course, if you get to spend extra time with your family, that's worth something also.
And lounge access on those international trips. That's worth something.
For my trips, CPM is part of it, but on long trips I'd rather be able to sit up front, meaning VIP availability is important, even at a slightly higher CPM.