More than 50,000 software developers have signed up to use web services technology that allows Amazon.com products to be incorporated into third party web sites.

The online retailer launched Amazon Web Services in the US in July 2002 before extending it to international operations including the UK in March last year (Computing 18 March 2003).

The success of the scheme shows that the emerging technology has a valuable business use, says Jeff Barr, Amazon's web services evangelist.

'Web services is new and very exciting. We are one of the few providers that has made it clear that it's not just a technology, but there's a business model to go along with it,' he said.

The company provides a toolset for developers to set up ecommerce offerings using Amazon's catalogue. Web site operators receive between 2.5 and 15 per cent of the value of goods sold.

Barr says Amazon is signing up 100 to 150 new developers a day.

'It's certainly working well and it's something we are investing in and growing,' he said.

Developers that use the service can choose an XML or Soap-based version. Barr says XML is easier to use and has proved far more successful, with 80 per cent of developers selecting this option.

He says the rewards Amazon is achieving from the initiative are significant.

'We are able to extend our reach and we can give customers more,' he said.

'This is giving us a lot of credibility in the developer community. It was a very bold thing to do. Outsiders questioned how Amazon could do this, and thought it was technically infeasible.'