American Express buying flights as if you redeemed miles

American Express is offering a promotion to a random selection of cardmembers likely to make up for losing American Airlines and United Airlines as transfer partners.

For flights that have award space on these two airlines, members can call the number and spend the equivalent number of Membership Rewards points, and Amex will BUY the ticket for you.

For example, if there is availability for a one-way United flight on First Class between LAX and LHR for 25,000 MileagePlus miles, you can spend 25,000 Membership Rewards points and Amex will purchase the ticket for you!  If the ticket was $4500, then it would have cost 450,000 Membership Rewards points to purchase if you did the standard "purchase flight using points".

The benefit to this is that you will still get elite-qualifying points and miles, where you would not have if you had just transferred into miles and done an award redemption!  In that regard, you can double-dip!