Instagram users with more than 1,500 followings are identified as Mass Followers.
In most cases, Mass Followers take advantage of automatic follow/unfollow third-party services. They try to grow their follower count in an inauthentic and largely ineffective manner by following large numbers of irrelevant accounts in hopes of a follow-back.
According to the Instagram algorithm, posts from Mass Followers do not appear in a user's feed updates, which significantly limits their value as an audience.
How Mass Followers fit into the Audience Type classification
The Audience Type section also includes Real People, Influencers, and Suspicious Accounts. The followings count takes the highest priority in classification: if an account has more than 5,000 followers but also more than 1,500 followings, it is still classified as a Mass Follower rather than an Influencer.