I'm not sure if anyone here is a member of Airmiles (not BA Miles, but www.airmiles.co.uk). I've just received a note in the post that if I use the Duo American Express card (presumably not the Mastercard) three times during March that I'll receive a 500 mile bonus. Not sure if this is widespread, or a targetted offer. But it may be worth buying a few coffees with the card just in case since there's no minimum amount to spend. It's not a bad deal. It costs 750 miles for a LHR-CDG return, for example.