I'm co-founding a start-up that is developing an e-commerce app. We're trying to decide what features to build in that shoppers would expect to see in order to feel comfortable submitting credit card orders: SSL, clear return/privacy policies, a "seal of approval" badge (e-trust, BBB), 800 number/chat for customer questions, etc...
So my question is simply what is on your list of security and consumer trust "must-have" features when installing any kind of shopping cart on your site?