In simple terms, the interaction rate is a calculation of how many likes and retweets you get compared with your number of tweets and followers.
Think of it as a proxy for how much people are vibing with your content.
And Mr Trump is going backwards — dropping from 0.27 per cent over the previous 12-month period.
So as the President racks up followers, he’s not necessarily gaining new supporters.
In all, Mr Trump comes 16th for interaction rate compared with all the declared Democrat candidates.
In a country like the United States that doesn’t have compulsory voting, one of the key challenges for a candidate is to get voters engaged and to the ballot box.
Mr Trump might enjoy having millions of followers, but that doesn’t mean much if they’re peppered across the world and made up of looky-loos and journalists on the POTUS beat.
If a rival politician with even a fraction of the followers can mobilise an engaged base on social media, it could build.