The Value of a Fan study was conducted by Millward Brown and Dynamic Log, in partnership with the World Federation of Advertisers (WFA).
It ranks the engagement of fans on a brand page using a FanIndex, scored by surveys completed by 3,687 fans, and compares this to the number of fans a page has.
Although there is a correlation between the FanIndex rating and the number of fans on a page, it found that some smaller sites achieve an above-average rating, and the page it looked at with the largest number of fans had one of the lowest ratings.
According to the study, the most successful brand pages are those with regular posts, trustworthy brand news, new information, contests and special offers.
Brands that are innovative and interactive on their pages are most likely to stand out from others.
The survey found that 96% of the 24 digital marketers expected to spend more time and money on social media in the next 12 months, despite the fact that half were still unsure about the return on investment it generates.
Brand insight, loyalty, advocacy and engagement were more important for them than achieving short or long-term sales.
Duncan Southgate, global innovation director at Millward Brown, said: "Fan expectation of brands in the social media space is increasing all the time, and marketers that do not regularly add new and interesting content to their fan pages and embrace what their fans want from the page, are missing out on an opportunity to build loyalty among some of their most important consumers."
Last week, Tesco, which has had a rocky relationship with social media in the past, launched its first official Facebook page.