Slightly off topic but I mention because there is discussion in this thread about MR point redemption values: As close a relationship as AMEX has with DL, I was surprised recently to see that the IDC MR point redemption to Delta is now less than 1 to 1 -- i.e. 100,000 MR points = 90,000 Sky Miles. In the U.S. program, 1 MR = 1 Sky Mile.

Don't know if this is the case, but I'm wondering if this happened because the IDC program in recent years seems to have been lining up 100K MR points to equal enough points in each carrier's frequent flier program to be equivalent to an international business class ticket. Previously, Delta used to have its lowest mileage level set at 90,000 miles for U.S. to Europe in business elite. Now they have raised it to 100,000 miles.

So now it actually means that it is a better value to move points from IDC MR program into AF Flying Blue for redemption on either AF or DL than to move into the DL program, because 100K MR sent to Flying Blue would still have the value as a full business class ticket (on both DL and AF) while those sent to Delta Skymiles do not redeem for a full business class ticket on either airline.