Intersting thing about this certificate is the LIMITS on number of certificates you can order:

Delta: 100
UNited: 40
U-S Air: 100

It says American and Northwest and TWA do NOT have certificate limits.

So according to the rules you can earn as much as 50K miles.

ONe complaint though: the procedure is you mail the proofs of purchase to H-C, they mail you the certificate than YOU HAVE TO MAIL IT TO THE AIRLINE. TOO cumbersome for me. Why not give H-C your frequent flyer #, send in the proofs AUTOMATICALLY credit the miles.

Also: certificates can be lost in the mail and if you get them too late they're expired.

OMNI: These folks in teh TWA AMbassadors club are looking at me funny because I'm sitting here ripping coupons out of the sunday circulars. HEY! Like MIles I saw "SHOW ME THE COUPONS!!!" (Esp with double coupons at my Shop Rite!)