MILAN: Major brand owners may have artificially large fan bases on Twitter, as many of their followers on the microblogging service are "bots" rather than real users, a report has suggested.

Marco Camisani Calzolari, a professor at IULM University, assessed whether the followers of 39 firms could be "bots" – namely, automated accounts sending out spam or part of a network accepting payment to become fans.

As a result, it was estimated that 46% of the 1.5m followers of DellOutlet, the IT giant's resale feed, might not be genuine Twitter members.

"We don't control who follows any of our Twitter accounts and we don't artificially increase the number of followers," Richard Binhammer, Dell's social media relations manager, told the Financial Times.

"While there are some tools that claim to identify bots, they are not 100% accurate. The only action we could take is to 'block' a follower. We certainly would not want to risk 'blocking' a potential customer. Our focus is on relationships and engagement with customers."

The comparative total stood at 44.3% for Whole Foods, the grocery chain possessing 2.6m fans. Jet Blue, the air carrier boasting 1.7m followers, posted 36.6%, and EA, the games group with a Twitter audience of 1m, recorded 29.7% on this measure.

YSL, the fashion label, completed the top five among the operators analysed, with roughly 900,000 followers, of which 24.7% did not typically exhibit "human" characteristics.

"Many of the companies included in the research have delegated their public relations activities on social networks to web agencies that in some cases have taken short cuts in order to demonstrate to companies, who are oblivious, that their activities have been successful by generating lots of new users," Calzolari warned.

By contrast, Starbucks, the coffee house chain and one of the most popular brands on this platform with 2.5m connections, saw the headline figure fall to 6.9%.

Samsung Mobile, the wireless devices specialist, and PlayStation, Sony's games console, each had 1.3m fans, just 11% and 12% respectively may be "bots". This share hit 13.1% for the 550,000 users engaging with Coca-Cola.

In determining these findings, the study looked at the "human" traits of Twitter accounts, such as if their profiles contained a name, image, biography and address. Punctuation, message content, connection levels – like being "retweeted" – and logging on through different channels, also featured.

Where accounts met these and similar criteria, they received points as "actual" users. Otherwise, they were awarded points as "bots", with those registering higher totals on the latter metric assumed to be "false" followers.

Data sourced from Financial Times; additional content by Warc staff