I should add that, as a customer of Square's customers, I breath a sigh of relief every time I see a restaurant or small business using Square for point of sale. It means I'll get email receipts, that I won't have to calculate tips, that I'm unlikely to get mischarged, that my credit card info isn't passing through some half-assed amateur homebrew system, etc. It means I'm not trying to understand whether to push X or the green button for credit rather than debit, it means I can write a nice signature with my finger rather than some terrible low-res scratch with a bad plastic pen in a tiny box, etc.

As someone who uses other people's payment systems, Square makes me happy. It's a product that respects the users.