Cool solution! But how would this work for a business larger than a 1 person micro business. What about backend office stuff like accounting? Is the analytics collected compatible with accounting software? Do I need a computer? Also, an obvious flaw, is that customer can't see the total displayed. Turning the ipad around every transaction isn't convenient.
Even for a micro business the card fees are too much. With the weak economy, I've seen stores accept only cash.