Digital Overtake print by 2018?

A recent survey carried out for the prestigious Frankfurt Book Fair, which consulted 840 experts in the international publishing industry, concluded that digital publishing sales will overtake print sales, in 2018. Presently, however, the proportion of digital sales is comparatively low.  These conclusion were reported in a recent post of the Bookseller.com and the views probably represent publishing as a whole; developments within academic/research publishing are likely to be quicker.