When will books show up as part of digital sales in UK?

The Bookseller has a similar story to a Guardian report on high sales of books

But the comments question how the various numbers fit together. Some of the extra sales may have been though supermarkets.

Meanwhile the BBC report increased digital sales for the year

e books are not much mentioned in this.

Based on looking in on Exeter John Lewis this morning I think the shift to tablets from e readers is continuing. They have e readers quite close to tablets but in a different section and there was nobody looking at them. Maybe one visit is not really a test but I think longer term it may matter more for book publishers to be seen as part of what is available on tablets etc.