This BBC article states that on-line sales in the UK have increased:
Total Visa transactions
Q4 2001: 14.5 million
Q4 2002: 31.1 million
Sales volume
Q4 2001: 1.1bn euros
Q4 2002: 2.6bn euros
Fastest growing sector: Tourism/Entertainment, +531%
Slowest growing sector: Services, +57%
See also the Visa website for more statistics.