"Smart" credit cards may be over before they started

Smart credit cards, combining several credit card accounts on a single card, promised big improvements over traditional credit cards -- but they've had a rough ride. And now it looks like the journey is ending, with the last of the major would-be disruptors throwing in the towel. Plastc, in development since 2014, sent a letter to backers last week announcing that it was ceasing operations.Over the last year or so, virtually all of Plastc's principal competitors have done the same -- Coin, Strat