Here is some scoop on Transmedia and DALC.
You pay with the Transmedia card then your credit card gets billed. So, I get ten miles from Transmedia then net a free one mile on AMEX. So I can end up with 11 miles per dollar.
Same system on DALC, but you pay with the credit card. Don't try to register the same card for multiple programs on DALC. The last FFP is where the miles will be credited. And if you try to register the card again the computer will find it on another program.
Also you can buy other stuff with either program catalogs, a few hotels, etc.
But, I think there is not a 6000 mile per meal limit on the Transmedia card like the DALC program. (Yes, that is enforced.)

The Transmedia points accrue like the AMEX so you can choose which airline you want. DALC's are automatically credited on your FFP statement.

I use both, they are very handy when you are responsible for entertaining recruits on your company's tab.

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