The concept of tablets ­ portable, lightweight and thinner than conventional laptop computers ­ has existed for decades. The arrival of Apple¹s iPad, however ­ with its characteristic multi-touch screen ­ proved a landmark release. Following its launch in April 2010, three million units were sold in the first 80 days, and thanks to the release of the iPad 2 on 25 March 2011, 4.69 million units were sold in the second quarter of the year ­ or 311,666 per day.