Many e-commerce web sites are likely to fall down this festive period because IT teams have failed to anticipate spikes in demand and are cutting corners in web application development lifecycles, according to experts.

These problems occur because e-retailers often build new functionality on their sites in response to commercial pressures, without including performance testing and capacity planning in the development cycle, argued Scott Gilliland of consultancy Accenture.

Newly released research by the consultancy suggests that companies which engineer performance into their systems spend just five percent of their budget on fixing problems, while those who omit performance planning and testing spend 16 percent of their budget on fixing problems.

"We see the pressure of time or finance is forcing companies to cut corners, " said Gilliland. "There's a lot of misunderstanding in terms of what customers will do if the site is not performing – firms don't understand what will happen if customers run into a ten second response time."

Phil Turnbull of web hosting firm Hostway argued that a poorly performing site can affect the bottom line and impact customer loyalty, which is potentially much more serious.

He also predicted that even big name retailers could be found wanting this Christmas because they fail to adequately test their web site infrastructure.

"It can be a huge undertaking, especially companies which have a very wide range of offerings and a large customer base," he added. "But the [web site infrastructure] is only one part of the jigsaw – if you're not able to fulfill orders once they're taken this could have a potentially worse effect on brand loyalty."

Turnbull argued that widely available virtualisation technology now enables web hosting providers to quickly and easily scale their customers' server requi rements up and down.