I'm not asking a question - just sharing info. I also don't mean to re-hash the same info, but... Am currently in Paris. It was exactly 1 year ago I was in Paris with my trusty Capital One card but was unable to purchase metro tix with it (It's not chip & pin). Before this trip I obtained the Andrews Federal Credit Union Chip & Pin Visa (with a chip and a real PIN). Just to test the self service metro ticket machines I tried my cap1 card and of course it was rejected just like last year. Then I tried my AFCU Card, slid the card into the reader and waited expecting to type my PIN on the keypad. But no PIN was asked for...it just accepted the charge and my AFCU worked just fine. That's good - at least I got tickets. I bought several carnets for 2 days in a row with no problem. Today I go to buy 1 carnet and now the machine would not accept my AFCU card. I tried at the window with the attendant sitting there and it was rejected. Luckily I just needed 1 carnet and had cash so I used the machine and just put the cash in. Yes, all of my Card issuers have been notified of foreign usage.
All this to say - if you don't have a chip & pin and you don't have cash - forget about buying a metro ticket. If you do have a chip & pin you'll "probably" be ok - but don't count on it 100%. It just seems that the Paris Metro machines are unpredictable even if you DO have the correct cards.
Lastly we've encountered a number of annoying metro problems with metro cards breaking down, RER trains breaking down, etc. I just seems like an abnormal amount of problems. Sometimes the attendants are "kind of" helpful and other times treat you like you're a pain in the **s.
Buyer beware ;-)