UK online sales rose by more than 50% in the three months to Christmas, according to an industry survey.
Internet sales between 1 October and 31 December hit £15.2bn, up from £9.61bn a year earlier, with electronics and clothing doing well, Capgemini said.
Firms with both a High Street and online presence, such as John Lewis, did best, the survey said.
For every pound spent on goods in 2007, 15 pence was spent online, pushing annual electronic sales to £30.2bn.
In 2006, for every pound spent on retail goods, the internet spend had been 10 pence.
"There can be no doubt [that] online is growing its share at the expense of bricks and mortar retailers and we believe this trend will continue," said Anthoula Madden, vice president at Capgemini's consumer products and retail division.
Online shopping peaked during the first week in December, with sales rising 9% year-on-year.
However, in previous years the busiest period had been earlier, signalling that consumers were delaying spending, to take advantage of discounting before Christmas.
Retailers have painted a mixed picture of results covering the crucial Christmas period, but several firms have highlighted the strength of their online sales.
In its latest trading update, music shop HMV said its bookstore chain Waterstones saw internet sales double in the five weeks to 5 January.
Argos, which is owned by Home Retail Group, said internet orders increased by a third in the 18 weeks to 5 January, representing nearly a quarter of all sales at its Argos stores.
The firm said its online reservation system for collection in store proved particularly popular.
Tesco said its online businesses had a "very successful" Christmas, in the six weeks to 5 January, with strong demand for MP3 players, digital cameras and laptops sending total sales 24% higher.
Even Marks & Spencer, though seeing its worst Christmas sales for more than two years, saw internet sales surge 78% in the last three months of 2007, year-on-year.