Square, a six-year-old start-up which provide card based payment solutions to retailers is now valued at $6 billion. It's original business was based on a small square dongle which plugged into a tablet device which would take mag-stripe card payments through the Square payment provider. Because of the growing adoption of Chip & PIN in it's largest markets, the US and Europe, Square have now decided to launch a Chip & PIN reader. As retailers struggle to build Chip & PIN PCI compliant payment solutions for the popular staff assisted tablets and mobile POS, this solution could well end up being the remedy.