Influencer marketing and SMM has such term as "engagement rate" of the influencer's audience. This is a parameter which helps you to determine whether the influencer is interesting to followers and whether they trust him/her. Engagement rate is calculated by the ratio of the follower's number to the number of likes, comments, and views. It means that if you want to define the engagement level of one publication, you should divide the total number of interactions (likes, comments, shares) by the number of followers. Then multiply the receiving figure by 100%.
A good result for micro-influencers (10K-100K followers) will be 4-8%, for middle-influencers (100K-500K followers) — 2.4%, and for macro-influencers (500K-1M followers) — 1.7%.