E-traders must prepare their sites now for the spike in sales during the next Christmas period, or risk not being able to meet demand, IT consultancy Conchango has warned. Firms that do not start to upgrade soon may be too late, it added.

Online retail sales increased by 91 percent in 2003, and such growth is likely to continue for a number of years.

The Interactive Media in Retail Group estimates that by 2009, a quarter of all UK shopping will be conducted via the internet or mobile devices in a market worth £80bn.

Mike Altendorf, managing director at Conchango, said that to meet the Christmas rush, firms would typically need to have IT systems in place by October. He estimated that it would take at least three months to develop, test and analyse the performance of upgraded sites - so firms should begin their preparations now.

"All retailers ought to be planning their Christmas promotions months in advance," Altendorf said. "If they promote them then they will generate traffic. Web sites must be ready to work effectively under this strain, but companies must also ensure that they can integrate their sites with the other areas of business. Online is no longer a silo concern."

To help firms, Conchango has made available an "online readiness tool" that firms can use to analyse the performance of their sites, and judge how usable they are for customers. Called the Retail Web Optimiser, the tool looks at how customers interact with sites and make payments on them.

Conchango can then analyse this data and recommends site improvements where appropriate. Although the tool is free, customers will have to pay for this analysis, Conchango said. The areas assessed include design and navigation, fulfilment and customer service, rates of online customer churn, and the quality and range of merchandising and promotional campaigns.

"Last year was a major watershed for online retailers, lots of whom were not ready for the increased demand," said Altendorf. "Many firms have not invested in their sites in the last two to three years but have seen massive growth in their use. Retailers must understand that if they want to be competitive, they must give customers the ability to do precisely what they want."