Supermarket giant Tesco has proved an unlikely hit with the Facebook generation, after more than 260,000 people joined its social network in the past three months.

ChannelAdvisor revealed Tesco had one of the fastest-growing retail Facebook sites, with over 300,000 ­registered 'fans' signing up since its March launch.

However, not all of them are positively minded towards the retailer and it has admitted its rise up the online rankings had come at a price allowing customers to complain about everything from lack of availability to poor service and even the size of vegetables.

"Since Philip Clarke started [as global CEO] this March, Facebook, as well as wider social media, has been important in fulfilling his innovative strategy," said a Tesco spokesman. "We have had to realise that with social media you can't control the comments but we have had many incidences when it's actually the users who stand up for us against some of the more negative comments."

The retailer saw a flurry of activity on its site when customers bombarded it with calls to stop advertising in and selling the News of the World when the phone hacking scandal peaked in July. That controversy alone added more than 1,000 'fans' to the site.

A snapshot survey by The Grocer of the Tesco Facebook page this week found more than a third of comments posted were critical of Tesco.

"You are always going to get negative comments but it's about how you deal with them. Tesco is benefiting from engaging with its customers," said Simon Besley, account manager at ChannelAdvisor.