Vitrue, the digital specialist, has conducted its annual assessment of the brands producing the most electronic word-of-mouth, based on data drawn from a range of Web 2.0 portals and a variety of blogs.
It analysed the frequency and tone of comments made by consumers, but excluded services like Facebook, Google and YouTube from its ratings, as they are major components of the social media space, and facilitate the sharing of such information.
Reggie Bradford, Vitrue's chief executive, said the success of the iPhone – which was also pre-eminent last year – was unusual, as it did not have a formal presence on Facebook or Twitter.
Apple's broader popularity in this area was shown by the fact that its iTunes music service came in sixth, helped by its activity on Facebook, while the company itself was in eighth.
By contrast, the iPod now resides outside the 30 best performers, having taken seventh position 12 months ago, one spot ahead of the Mac, which slid to 35th this year from 16th in 2008.
Sony, the electronics group, was one of the few other firms to appear twice in the top 20, with its corporate brand and PlayStation games system both among this group.
Microsoft, the IT giant, recorded a similar result with its trademark brand and Xbox gaming machine, further demonstrating the strength of the technology sector as a whole.
Coca-Cola was accorded the status of the world's most valuable brand by Interbrand last year, but it was down nine places, to 31st, in Vitrue's rankings.
IBM, which was second in Interbrand's 2009 poll, claimed 90th in Vitrue's standings, while Microsoft, which was in third in the branding specialist's figures, took 18th when it came to online "buzz" metrics.
The Altimeter Group, a digital consultancy, has also produced a report suggesting that Dell and Starbucks were the two companies making the most effective use of social media.
Vitrue, however, downgraded Starbucks from sixth position last year to eleventh place this, while Dell plummeted from tenth to 30th over the same period.
Other brands posting major declines included General Motors, down from 31st to 85th, Pepsi, down from 30th to 73rd, and Fox News, down from 19th to 54th place.
Joseph Jaffe, president of Crayon, the digital agency, said marketers must look beyond simple statistics like their number of "friends" when assessing their performance in this area.
"Being a social brand is not necessarily proportional to social media adoption. It's an attitude and much more likely to be a cultural variable than having 12,000 Facebook fans."
Data sourced from Adweek; additional content by Warc staff