Among the issues for the retailer is whether to build its social-networking platform on an established site like Facebook, or whether to set up an independent site with the retailer's own brand. External sites like Facebook and MySpace might become less important if big companies can attract audiences to their own sites, he said.

The retailer has only just started to explore these issues. "It's still very early; we're still in perspective-gathering mode," he said.

An assistant marketing manager from a U.S. tobacco company also was at the show to explore how social networking could help attract a community around his company's products. Some smokers are passionate about their brand and have registered at the company's site, helped by offers such as vouchers for cheap cigarettes, he said.

However, tobacco companies face particular challenges. The U.S. government has been passing tougher regulations for the industry, and some tobacco companies expect new laws that will require them to ensure that visitors to their Web sites are of legal age, by collecting names and even Social Security numbers, said the manager, who also asked not to be named.

"We have to be very careful about who we attract to our site," he said, adding that new regulations could make using third-party Web 2.0 platforms more difficult.