The deal, announced early last week, will see John Lewis taking over the technology and management team behind buy.com to develop its online department store offering.
Nigel Reeford-Brown, merchandise director at John Lewis, said the retailer bought the UK operations of buy.com for its technology and customer service offering.
"People shop with us because they trust the John Lewis name and we wanted to be able to simulate that same level of service on the Web site as in the high street. But the question was how. If we got it wrong, not only would it undermine the confidence of our online customers but it could also hurt our high-street presence," Reeford-Brown said.
John Lewis will gain the management expertise and technology it would have had to develop on its own. It will also benefit from an on-going technical support and advice agreement with the US parent company.
Roger Willmott, vice-president for IS at buy.com UK, said the buy.com's Internet systems would be linked with John Lewis' existing back-end systems.
Additional functionality would be built in over the next few months for the technology to form the basis for John Lewis' online offering.
The team of 30 buy.com IT staff would work with John Lewis in-house staff and the integration of the two systems was likely to be completed by the end of August.
Willmott said, "One of the best things about this [on-going relationship] is that with the US being two years ahead in terms of market and technology, it will be like a crystal ball for us."