The half-life of a social media post is the time it takes for a post to receive half of its total engagement (such as likes, shares, and comments). Scott Graffius, who uses copious amounts of data, releases an updated report every year on this, and for 2024, here are the results (I have rounded the numbers).
Noticeably absent is TikTok. In 2021, Graffius included TikTok. At that time it was 0 minutes...except in the case of viral videos, which tend to have much longer life spans, obviously. I imagine with the increase in the length/time of videos this number has likely changed to a bit longer half-life, but without the data, it doesn't serve anyone to guess.
Marketers love knowing these numbers because it helps them know how often to post.
I use them to point out a few things:
--> Regardless of these numbers, what you say and how you say it matters. A post from 10 years ago can still sink you. Be the version of yourself online that your grandma would be proud of. P.S. You should also be this version in real life. No one likes a meany.
--> Posts are gone quickly, so consistency of message is important. Know who you are, who your audience is, how you can help them, and clearly share content that helps them...repeatedly.