Online sales are expected to double and account for 20 per cent of all retail sales by 2010, according to online retail research group IMRG.

Internet sales are already booming growing more than 3,500 per cent since 2000 to an expected £42bn this year. This figure will likely rise to £78bn by 2010.

And international sales could be the next growth area, with global internet shopping worth more than £250bn this year.

‘Whereas the value of UK online sales will double by 2010, its international e-retail trade is expected to increase by 1,000 per cent in the same period,’ said IMRG in its annual statement on the state of the e-retailing industry.

‘Developing a thriving e-commerce sector that reaches beyond national borders will become vital for the competitiveness of every country’s economy.’

Last year online sales will reach £30.2bn, up from £19.2bn last year, with sales over Christmas surpassing all expectations and to generate almost £1bn during each of the first three weeks of December.

This year, an estimated 860 million parcels will be shipped to the UK’s 26 million customers, with every online shopper expected to spend an average of £1,600 this year.

But despite the clear success of online shopping, nearly half of the top 100 retailers do not have a web site from which purchases could be made, says IMRG.

Such retailers are also missing out on the opportunity to pitch themselves as the eco-friendly alternative to travelling to high street shops.