First, the good news for readers: ListenFirst, the provider of this chart, has expanded the universe of brands tracked here to include not only Ad Age's list of the 200 biggest advertisers but also any other top brands in the Redbooks 500, meaning you'll see more movement and surprises week to week.
Now the good news for Citi and IHeartRadio: They proved this week that they can go toe-to-toe in social media with powers like Starbucks and the NBA, with Citi's Facebook post about sustainability and iHeartRadio's tweet to promote voting in the iHeartRadio Awards generating more engagement than any other marketers' posts on those platforms. (If Stephen Curry's incredible season has helped the NBA's post generate likes and retweets, it seems fair to note that iHeartRadio's winning tweet included a call out to the #MendesArmy, fans of social-media star, and singer, Shawn Mendes.)
We're using data on the week through Sunday provided by ListenFirst Media, which closely tracks engagement using measures such as likes, shares, comments, views and thumbs-ups. See the week's full chart and the posts themselves by clicking on each here:
Methodology: Marketer MVPs surfaces the individual brand posts, both paid and organic, that generated the most engagement on Facebook (defined as likes, shares and comments), Twitter (retweets and likes), Instagram (likes and comments), Tumblr (original notes) and YouTube (official views, comments and thumbs-ups). Brands tracked are the 200 most-advertised brands by U.S. measured-media spending in 2014, per Ad Age Datacenter, in addition to the top 500 brands as identified in the Redbooks 500.