Device sales numbers may be difficult to nail but they’re an easy ride compared to usage statistics.

In the UK at least, all the large retailers including Amazon, have been popping up to remark on the relative increase in mobile commerce they’ve experienced over Christmas. Many are reporting over half of all their online traffic has been generated by mobile devices. National UK department store chain, John Lewis, for instance, says smartphones and tablets accounted for a full 76 per cent of the online traffic generated by its post-Christmas clearance sale.

In the US it was more muted - IBM’s retail tracking arm put mobile traffic at 48 per cent of all online traffic on Christmas Day, but that was up from just 28 per cent in 2012.

Given those stunning first-hand results, what are we to make of almost diametrically opposed numbers from the likes of StatCounter. It measures Internet usage across devices and national boundaries and in December it released statistics on tablet and smartphone v. desktop/laptop ‘conventional’ computer engagement on the Internet.

Measuring traffic in November takes out ‘holiday’ usage and factors in full-strength office usage. It found that tablets globally accounted for just 4.8 per cent of internet usage compared to mobiles at 19.1 per cent and desktop and laptop usage still dominating at 76 per cent.

Despite the huge sales uptick for tablets over the past few years, and despite much propaganda proclaiming their eventual complete replacement of old-fashioned PCs, it ‘appears’ that they have yet to be used consistently to displace ‘conventional’ computer usage... except perhaps at Christmas time.

Then, of course, tablets and - especially - smartphones are presumably used to buy gifts or to fill idle hours online shopping in the post-Christmas sales. PCs and laptops, on the other hand, are ordinarily used for more ‘heavy’ interactive work both at home and at the workplace and therefore still figure highly in the engagement stats - especially in a relatively neutral work month like November.