In days of yore, paid-for purchases were all that mattered - but we live in sophisticated times, and more than five out of every six singles 'sales'  these days are actually conjured up by the magic of streaming. Were things as they used to be, we would this week be heralding the second No.1 single of 2012 X Factor winner James Arthur, who previously topped the chart with his coronation single, Impossible, and had by far the biggest selling single ...