The bad news from Webtrends, however: Facebook’s GraphRank algorithm filters out content from brand pages that doesn’t engage users, and posts using language such as “percent off,” “coupon,” and “sale” result in the lowest engagement levels, leaving them in danger of being filtered out of users’ news feeds.
This prompted the company to create the Sociability Index, which examines click-through rates and cost per click to determine what type of content is “fun to talk about.”
One tip from Webtrends is:
Industries with low Sociability Index ratings need to carefully consider their ad topic in order to gain better CTR. For instance, if an insurance company sponsors a big football game, an ad for fans that highlights the game will prove better CTR than if the ad is directly selling insurance.