Revenue increased 11.9% in Q1 of 2015, to $17.26 billion compared with $15.42 billion in the year-ago period.
U.K. shoppers will spend $1.5 billion via mobile devices during the holidays.
Roughly 20% of U.K. shoppers' online spending, about 920 million pounds ($1.5 billion), will take place on mobile devices during the two-week period beginning Dec. 3, according to the IMRG Capgemini eRetail Sales Index.
Overall, U.K. consumers will spend 4.6 billion pounds ($7.3 billion) during that period, say consulting firm Capgemini and e-commerce trade association Interactive Media In Retail Group, or IMRG.
"What we are seeing in this 20% mobile forecast is a shift in the way that consumers interact with brands online," says Tina Spooner, chief information officer at IMRG. "While it is still common for consumers to browse the shops at weekends before making the final purchase online at Monday lunchtime, we are increasingly seeing the popularity of 'second-screening,' where people browse on their mobile devices in front of the TV."