• by Mark Walsh  @markfwal, November 19, 2012

Facebook unsettled marketers in September when it altered its EdgeRank algorithm -- which determines what someone sees in their news feed -- ostensibly to reduce clutter and improve the user experience. It acknowledged that the changes would diminish the number of organic brand posts people see, but help increase engagement per post.

A new study released today by WPP's GroupM suggests that users are indeed being bombarded with fewer organic posts, but that the dialed-down exposure has led to increased interaction as promised. The proportion of Facebook users that see an organic brand post has fallen 38% from 15.5% to 9.6%, following the EdgeRank update.

At the same time, the average engagement rate has nearly doubled from .76% to 1.49%, according to the GroupM study, based on an analysis of 25 brands on Facebook by its Next Predictive Insights team in conjunction with M80, the agency’s social media unit.

That sounds like a reasonable tradeoff, but GroupM points out that while marketers see more interaction per impression, they are also seeing fewer total impressions. “Taken together, these trends mean that advertisers should not expect an increase in aggregate volume of engagement of their posts on Facebook,” the report stated. "This result means that brands are not gaining additional organic engagement as a result of the change and are only losing organic reach."

In short, the lift in engagement is not enough to offset the decline in reach on a site with more than 1 billion users. The results can be seen as supporting speculation that Facebook’s real goal with the algorithm changes was to boost demand for its paid solutions, like promoted posts and Sponsored Stories to broaden reach.

But GroupM says the EdgeRank change also provides deeper insights that can help update their earned media strategy on Facebook without becoming solely paid-dependent. The reach of status updates, for instance, increased almost 20% -- even while brand posts like photos, videos, links and “shares” fell off dramatically.

The findings show that organic posts are now being better targeted toward users with higher brand affinity. Still, GroupM suggests the importance of engagement on Facebook has been overstated at the expense of reach.

Based on its research, the media buying giant advises brands to gain a better understanding of the impact of page post types and use that data to inform the type of content it publishes, as well as the pace of messaging. By adopting an optimized posting strategy, it indicates that brands can boost reach on Facebook by 28%. That will not get brands back to the 16% reach they had before the EdgeRank change, but would help regain some of the reach lost.

Facebook itself has encouraged companies to use a combination of earned and paid media on the site to achieve the best marketing results, backed up by a series of studies conducted with comScore. The latest "Power of Like" report found that brands can reach five times as many people by using advertising to amplify page content.

In a statement today, Facebook rejected the notion that it changed its algorithm so it could charge marketers to promote posts. “This meme is totally false. News feed is built to show relevant content. A few times a year we perform quality checks on the news feed algorithm to ensure high-quality and relevant posts,” the company said.