Love the concept but the security worries me. Looking on the site, there is (as expected) not much information about security.

RED FLAGS:

* Coin is in the process of earning a PCI certification. This should have been done before launch. Also, what level? * Coin uses 128/256bit for security but HOW and WHERE? * Coin essentially skims cards (through the reader) to playback for terminals. I don't see how they can say with a straight face that it is less susceptible to the same techniques. * Adding what are supposed to be funny Q&As to a FAQ trivializes what are supposed to be important questions for people thinking about using this. * I understand the love of "the cloud" but I wish people would also consider scenarios for a disconnected model. These are solutions that do not necessarily require a full time connection.

I could see using this for pre-paid gift cards but not for my actual credit cards.