America's etail market was worth $50.4 billion (€40.3bn; £26.9bn) last year, a surge of 26.3% on 2002.
The figures, released by the Commerce Department, show that the US ecommerce sector outpaced general retail sales, which rose 5.4% in 2003. As a result, online purchases grew from 1.3% of total retail in 2002 to 1.6% last year.
Christmas appears to have been a particularly strong period for online sellers, with the internet accounting for nearly 2% of all national sales during the final quarter. And the rapid growth in etail appears to have continued into 2004, with early reports indicating a 40% year-on-year rise in Valentine's Day purchases.
The Commerce Department data, based on 11,000 retailers, omit online travel agents, financial brokers and ticket sellers. Some analysts estimate that, if these sectors were included, ecommerce last year could have topped $100bn.
Data sourced from: BBC Online Business News (UK); additional content by WARC staff