NEW YORK: Brands hoping to succeed on Facebook must adapt their approach, as changes to the social network's system for prioritising information has cut their reach but aided engagement, a report has argued.

GroupM Next, part of WPP Group, assessed 25 brand pages to see if alterations to Facebook's EdgeRank algorithm, dictating which items appear in users' newsfeeds, had impacted exposure and engagement rates for organic, rather than paid, posts.

It reported that 15.6% of brand fans on the site were typically exposed to these organic posts before this revision, compared with 9.6% afterwards, a 38% drop.

More positively, engagement levels - determined by tracking metrics such as the number of people watching videos and "liking" or responding to messages - rose from 0.76% to 1.5%, a 96% lift.

"The EdgeRank change means that the material brands post to Facebook is being better targeted by the network toward users with a high brand affinity," the study said.

When monitoring the types of organic content added by marketers, the reach of status updates jumped by 19.5%, whereas links logged a 68.2% decline and the exposure to "shares" fell by 59.1%.

Photos also registered a 40.5% decrease in this area, while video witnessed a 31.9% slide, the study continued.

Once again, upon assessing engagement rates, looking at actions like clicks, reposts and "likes", figures improved once EdgeRank was modified, with links seeing an uptick of 101.2%,

Photos recorded 73.5% on this metric, ahead of video on 57.1% and status updates on 56.8%. "Shares" constituted the only format to experience a decline, albeit a large one, of 125%.

In all, roughly 2.7% of impressions resulted in some kind of user consumption before EdgeRank was modified, rising to 4.3% thereafter, a 59% increase.

The level of improvement hit 129.8% for links, as well as 44% for video and 34.9% for photos, whereas status updates endured a 13.9% contraction and "shares" were down by 291.8%.

When assessing what it categorised as "engaging material", GroupM Next also discovered that the best content delivered a 71.4% lift in engagement prior to the change, and just 21.4% afterwards.

"Engaging content still matters but, surprisingly, not as much as it used to. This is likely due to the fact that the small audience of fans reached is more likely to be predisposed to engagement, regardless of quality, and therefore individual post quality no longer requires as high a standard," the study said.

Data sourced from GroupM Next/AdAge; additional content by Warc staff