Amazon has been granted a US patent for the technology it uses to monitor users' shopping habits and suggest future purchases. 

Users are most familiar with the visible aspect of the technology which announces: 'People who bought this also bought ...'

Referring to it as 'Recommendation Technology' an Amazon spokesman said: " This is a key part of our technology and something that took thousands of hours to develop. We have done this to protect our intellectual property. This is a method of shopper analysis that is unique to us."

But some experts have suggested that this is an example of patenting a business model, which not allowable under UK patent law.

"Patenting law is crazy in the US. This wouldn’t happen here. After all, recommending new ideas to shoppers is something that has been going on in shops for hundreds of years," said Michael Chissick, head of IT and e-commerce at law firm Field Fisher Waterhouse. 

"As a result we recommend that e-commerce firms think hard about patenting technologies in the US because it is so easy for someone over there to see what you are doing and get a patent before you do."

Amazon currently has around 100 patents in the US and overseas. The company declined to say whether a similar patent is being applied for in the UK or across Europe.

The news comes days after a European Parliament committee approved a legislative proposal creating a single way of patenting software throughout the EU, for which many IT firms have been lobbying hard.

But the bill does not allow the patenting of business methods, or programmes like Amazon's 'one-click' shopping system which has led to litigation with e-commerce firms offering similar systems.