The ENGAGEMENTdb report was produced by Wetpaint, the social networking specialist, and Altimeter Group, founded by Charlene Li, co-author of the book Groundswell (reviewed here).
It assessed the top 100 global brands, as identified by BusinessWeek and Interbrand, to establish how effectively they were using the growing range of social media tools to engage with consumers.
Among the channels it analysed were corporate blogs, branded and customer communities, wikis, discussion forums, and sites like Facebook, MySpace, Twitter, YouTube, Flickr and Photobucket.
Starbucks posted an index score of 127, and operates across 11 different channels, as well as employing a social media team comprised of six people.
Its activities in this field include MyStarbucksIdea, which allows the coffee house chain's customers to submit their views and suggestions to the company.
The firm's Twitter account also has over 250,000 followers, and the brand's official page of Facebook has more than 3.5 million people registered as "fans".
Alexandra Wheeler, Starbucks' director of digital strategy, said "we live in the physical world with thousands of natural touch points, so when we laid out the vision for our social strategy, it felt like home for the brand."
"It's about the relationships we form with our customers, not marketing. We need to build our social strategy up with integrity so that we are not compromising the relationships with customers," she added.
Dell's move into the social media space initially followed on from a need to improve consumer perceptions following a safety scare in 2005.
Having originally established a "blogger relations programme", the company has now expanded its operations to include IdeaStorm, an "idea generation hub", and a number of different Twitter accounts.
Indeed, earlier this year, the computer manufacturer reported it had generated $3 million (€2.1bn; £1.8bn) in sales through the microblogging service.
Richard Binhammer, a senior manager in corporate affairs at Dell, said that "when we moved into other channels, we learned our lesson and adopted a conversational approach culturally."
These two brands were both described as examples of "mavens", or commercial entities that use seven or more social media channels, and have an above-average engagement score.
Other examples in this category – and which are typified by making social media "a core part of their go-to-market strategy" – include eBay, with an index score of 115, Google, on 105, and Microsoft, on 103.
Data sourced from ENGAGEMENTdb; additional content by WARC staff