With 3.3 billion mobile-phone subscribers worldwide, compared to only 1.3 billion Internet users, Cisco argues that handsets will soon be the "fourth channel" for retailers, taking their place alongside physical stores, Web sites and catalogues.

In a survey of 45 North American and European retailers, Cisco found 42% already provide the ability to view products on mobile devices. But only 15% offer the ability to conduct transactions, while 10% use SMS text messaging to provide customers with information and six per cent have Web pages and a URL specifically designed for mobile use.

Dick Cantwell, VP, retail/CPG practice, Cisco Internet Business Solutions Group, says multi-channel retailing has morphed into a Web of shopper touchpoints across stores, catalogues, mobile devices and the Internet. But he says retailers must start offering shoppers an "interconnected shop" if they are to take advantage of the mobile opportunity.

Cisco says e-retailer Amazon out-ranks other retailers by letting consumers conduct transaction on mobile devices.

Earlier this year Amazon launched TextBuyIt in the US, which enables customers to use text messaging to find products and make purchases using their mobile phones. To find a product, US customers send a text message to the retailer citing the name of the item or a UPC or ISBN code. Amazon then replies within seconds with details and prices of products matching the search query.

Cisco says the rise in social networking is also re-defining the online experience for customers and providing new revenue opportunities for retailers. A study of e-commerce sites found 52% already provide customer reviews for products and 50% have "advanced visualisation tools". Around half also provide multimedia such as video and 50% offer customer support through multiple channels, such as click-to-chat. Currently, only 17% provide the capability for users to connect to communities of interest.