Digging through some old mail today, I came across a mailer from Amex with an interesting offer.  10X Membership Rewards points for booking Delta Air Lines tickets through April 15, 2011, with your eligible card.  The offer is for flights between 2/15/2011 and 4/15/2011.  Visit http://www.americanexpress.com/delta10x to enroll.  Now…this appears targeted as there is an RSVP code.  That said, you also have the option of entering your americanexpress.com login information to register.  My point being that you should go to the registration site and check to see if you’ve been targeted.  Maybe your mailer got buried in a pile of unimportant looking stuff like mine.  Enter your amex.com login info…and you might get lucky.  In any event, your mileage may vary.