In Q1 2013, mobile commerce accounted for 20.2% of web sales in the U.K., up from 15.4% in Q4 2012, finds IMRG and Capgemini. Interactive Media in Retail Group, or IMRG, is a U.K. e-retail association. Capgemini is a business and technology consultancy.

Mobile traffic to retail sites as a percentage of total traffic reached 30% in Q1 2013, up from 24% in Q4 2012, the firms say.

IMRG and Capgemini attribute the spikes in mobile sales and traffic in the first quarter to a large increase in tablet owners following Christmas 2012.

Mobile commerce has grown at a tremendous pace in the U.K. Sales via mobile devices shot up from 0.9% in 2010 to 4% in 2011, reached 12% of e-retail sales in 2012, and hit 20.2% today, the firms say. Visits to retail sites via mobile devices have risen from 2.6% in 2010 to 8.2% in 2011, reached 21.3% of all e-retail visits in 2012, and hit 30% today.

“Mobile is clearly a game-changer for the U.K. e-retail industry—at the beginning of 2010 mobile sales accounted for just 0.4% of the U.K. e-retail market, and within three years it has surged a staggering 5,000%, with m-retail now accounting for one in every five online purchases,” says Tina Spooner, chief information officer at IMRG. “With the continuing shift away from desktop to mobile Internet use, it is inevitable we will see the latter platform outstrip desktop PCs as the preferred device for shopping online, and from the latest figures it is apparent this may be sooner than expected.”