Square Cash
That’s the premise of Square Cash, launching today for all debit card users in the US, using any email service. To use Square Cash, all you do is compose an email to a friend, type the amount you way to pay in the subject title, and cc cash@square.com. If it’s your first time using the service, you’re directed to Square’s website where you type in your debit card number — and you’re done. There are no accounts to create, apps to download, friends to add, surcharges to pay, or bank account numbers to look up.
They also have an iOS app to help send the e-mail. It seems to genuinely be free, although PayPal started out that way, too.
