Announced last week, Coin, the digital credit card that stores your other cards, is looking to make a home between payment processors, consumers, and businesses. However, this is more of a stop gap to mobile payments rather than a true alternative.As niche mobile payment apps continue to gain in popularity, the ultimate disruptor that gains mass consumer appeal will be the payment system that covers everything. Coin bridges the multi-functionality that's needed for mobile payments with the traditional physical payments we're all used to. It feels like an approach to onboard people to a future mobile payment platform instead of a game–changing product.While Coin's technology is patent–pending, if it does take off, competitors will find other ways to adapt the concept to their own payment strategies. Smart benefit credit cards that differentiate between health purchases, transit, and non-qualifying purchases, have been around for years. Adding more accounts to the cards and automatically charging the best account for each product or purchase is a logical next step. It's hard to imagine larger players not adapting similar concepts as short term solutions to on board more people to their mobile payment platforms. Since most of these companies make money off of transaction fees paid by the vendors, they could quickly challenge the consumer–charging Coin.It's a cool product that will certainly make life easier for some, but at $100 a card ($50 during pre-orders), I don't think it will gain mass market appeal without a large strategy shift for the product. Perhaps Coin's creation of Bluetooth Low Energy Developer Kits is part of that.