Square mobile card payments get Virgin seal of approval

The world's most famous Virgin - Richard Branson, not the other one - has confirmed that he's the latest investor in on-the-go credit card payment start-up Square, fronting an unspecified portion of the company's latest $100 million round of Series-C financing.

Square, created by Twitter founder Jack Dorsey, shot to fame when it released an add-on for the iPhone which connects to the 3.5mm jack and allows the device to read the magnetic strip on the rear of credit and debit cards. Some clever software later, and the company had produced a tool to turn the smartphone into a payment terminal.

Since its inception, the company has released software for the Android operating system as well as an update which allows the device to work on tablets, and has seen its customer base soar thanks largely to a decision to give the hardware and software away to its customers free of charge.

Combined with a surprisingly reasonable transaction fee, that's a recipe for success in a market where the incumbents charge hefty equipment purchase or rental fees on top of monthly service packages and per-sale transaction charges.

Although the company has yet to venture outside the continental US - despite promises that an international launch is on the cards - it's clearly caught the beardy one's eye.

"I’m very passionate about helping people start and grow successful businesses," Branson claimed of the deal, "and Square is an incredible technology that inspires and empowers everyone to be an entrepreneur."

That latter point - the fact that the technology can be used by anyone for any venture - does hint at some of the criticism that the company has come in for, with its early launch marred by claims that it would be adopted by drug pushers and other unsavoury types to allow for street-corner credit card transactions.

Those fears, thankfully, don't seem to have come to pass - and the creation of a third-party hack capable of accessing the Square payment system did little to slow the company's growth, relying as it did on having access to a pre-existing merchant account with which you get the official hardware anyway.

Having officially launched just one year ago, Square now claims to be at the head of a network of some 800,000 retailers who process more than $2 billion in payments annually. As part of the investment announcement, the company claimed it would be launching internationally in 2012 - although that's a refrain we've heard from the company before.

The company is under increasing pressure, however: since its launch, payment processing giant VeriFone has created a rival product of its own, while start-up Erply promises Square-like convenience with lower transaction fees.