Analysts said the move to Linux, which does not need multiple licences and can be customised to fit a particular need, was not surprising given the economic uncertainty and anger at Microsoft's new licensing regime, which some users have said will double software costs.
"Companies are finally looking at alternatives to Microsoft, particularly on the desktop," said Tony Lock, senior analyst at Bloor Research. Amazon's move could prove to be a catalyst for other companies to look at Linux, he added.
In a regulatory filing, Amazon said its IT spend in the third quarter of 2001 was £37m, compared to £48.5m for the same period last year - a saving of £11.5m, over 24%. In the first nine months of the year, Amazon spent £129m on technology, compared with £137m in the same period last year, the company added.
Amazon said the cost savings that have been made "primarily reflect its migration to a Linux-based technology platform that utilises a less costly technology infrastructure".
The reduced cost of IT services also contributed to the savings, the company said.
However, the company declined to comment on how exactly it was using Linux.
Lock added that now was a good time for companies to sit back and consider the options available.
"Companies need to understand their requirements - software such as Star Office [Sun Microsystems' office application suite] can give the vast majority of users everything they need," he said.