Instagram Suddenly Chokes Off Developers As Facebook Chases Privacy (techcrunch.com)
An anonymous reader quotes a report from TechCrunch: Without warning, Instagram has broken many of the unofficial apps built on its platform. This weekend it surprised developers with a massive reduction in how much data they can pull from the Instagram API, shrinking the API limit from 5,000 to 200 calls per user per hour. Apps that help people figure out if their followers follow them back or interact with them, analyze their audiences or find relevant hashtags are now quickly running into their API limits, leading to broken functionality and pissed off users. Two sources confirmed the new limits to TechCrunch, and developers are complaining about the situation on StackOverflow. In a puzzling move, Instagram is refusing to comment on what's happening while its developer rate limits documentation site 404s. All it would confirm is that Instagram has stopped accepting submissions of new apps, just as Facebook announced it would last week following backlash over Cambridge Analytica. Developers tell me they feel left in the dark and angry that the change wasn't scheduled or even officially announced, preventing them from rebuilding their apps to require fewer API calls.
This is what you get when you build off an closed-ecosystem API. Fuckerberg only cares about his shekels not you measly plebes. #DeleteFacebook #DeleteInstagram #FuckTheZuck
More info here - https://www.coffeewithsummer.com/blogging-social/stop-follow-unfollow/
Basically it is a slimy tactic to trick users in to following back, "friending back", and once that is done, the original user will unfollow. This results in a +1 follower for them, and over time it makes a person's account look like they're an influencer because they might have 10x more followers than the amount of users they follow. To the untrained, it also has the charm of seeming like validation - when someone with few followers follows YOU it makes you think wow, they're awesome AND they like me! But then they just unfollow you shortly afterwards and the con moves on to the next target.
There are sites that will do this automatically/programmatically for fee as well.