Square 1) They solved a really hard problem. Basically they opened channels for merchants that used to only be able to take cash to credit cards. I have alre

Square 1) They solved a really hard problem. Basically they opened channels for merchants that used to only be able to take cash to credit cards. I have already used this twice on the consumer end. Once at a concert to buy a tshirt, once a cupcake food truck downtown. 2) They did an exceptional job of design in both hardware and software. 3) They had a real vision on their own, 'Apple Style' where they saw the problem and had a vision to a real solution. They didn't have to make a MVP and keep iterating (not that doing that is a bad idea) but have a vision that turns out to be true is always very impressive to me. 4) They executed in a exceptional time period. They had everything in place from from engineer to design and operation in the amount of time other startups take to make a webapp that is much less as sensitive (read: involves larges of amounts of money in a traditionally slow industry).