Similar to previous uses of Instagram's algorithms, if you engage with these posts by liking them or commenting, the social network will search for similar content and present it to you in the future. You'll be able to follow hashtags through searches in Explore or simply tapping on one already placed in another post.
To distinguish from a hashtag post and a normal post, there will be a "prominent button" above all hashtag posts. If something comes up that you don't like, you can dislike the post via this button. Instagram said this won't completely unfollow the tag, but it will help train the service on which parts of a specific hashtag you find appealing.
Matthew Ogle led the team behind the new feature at Instagram, and he previously worked at Last.fm and Spotify. When he was at Spotify, he was the product manager that helped launch Discover Weekly, and he told The Verge there are a few similarities to the origins of Spotify's curated playlists and Instagram's new hashtag-following option.
“Discover Weekly wasn’t about teaching an algorithm to understand and then recommend music. We taught an algorithm to look at what the community was already doing with this building block, the playlist, and to take the best of what the community was doing and extend it in a new direction,” says Ogle. “Hashtags are kind of the same way. You have something that is working organically on the platform, how do we add just enough additional structure so that more people can participate.”Before the update, you could find hashtags mainly through searches in Instagram's "Explore" tab. Explore would become personalized over time and showcase posts that the app thought you liked, but there were no "like" or "dislike" options to further fine-tune the tab.
The new update will be rolling out to Instagram users throughout the day.