These 5 Start-ups Will Change the Way You Pay for Everything

Image via Square.com
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Square Cash

Square continues its quest for world domination with Square Cash, a peer-to-peer service that lets friends e-mail money.

"We get to design what we want to see in the world rather than doing what other people think should be done," Dorsey told Inc. magazine.

His guiding philosophy has paid off: The technology is so intuitive more than three million merchants use Square's Card Reader to process $12 billion a year in transactions.

That stat alone should sell users on the invite-only service.