Square had a simple idea—enable credit card transactions on mobile devices—that drew a lot of competition from PayPal Here, Intuit, Groupon, and others. But Square has only extended its lead. The key: channeling small-biz charm. "You'd go to your local pharmacy and say, 'Put this on Keith'; they'd have an account for you," says COO Keith Rabois (who announced he's leaving Square after the initial reporting for this story). He wooed local shops with a flat-rate subscription of just $275 per month, and landed the right to process payments for all 7,000 U.S. Starbucks locations. Now, it processes more than $10 billion worth of transactions annually.
[Square Bill: Quang Ho via Shutterstock]