Approximately 15% of UK book purchases are made online

"Recent figures indicate that the share of book sales going to the high-street chains is in sharp decline, squeezed on one hand by those even narrower book choices in supermarkets themselves, and on the other by the ever-rising internet. In fact, the proportion of UK book retailing taken by online purchases now stands – at around 15 per cent – at a lower level than many observers might have predicted. Amazon has not yet flooded the marketplace."
Source: Boyd Tonkin, The Independent, 27th November 2009