This will get us closer to hashtag-exclusive posts. With that option, you can post into a hashtag, a location or a URL, without polluting your main feed. I can post on #chess without annoying all my followers with things they don't care about.

It's a simple way to separate your feed in topics so that only the follows of those topics see your posts, regardless if they follow you or not.

Topic-based feeds are better social media.