After looking at our own client posts and some other more recent data from Visibility Planner, Queezly, and Copypress, I have created this infographic to give you some guidelines. I have looked at the social channels we use most for clients: Facebook, Instagram, Twitter, and Pinterest.
You can obviously extend the organic lifespan of any post with boosts and paid promotion. The good thing about this is that you can target specific audiences and set a timeline and reach. I also recommend using Facebook Live to extend your reach, content lifespan, and to engage new audiences on Facebook.
One other thing to consider is how often you should post on each channel. If you post too often on Facebook or Instagram, you can ruin your own organic reach of each post. This is different for news sources that can post frequently on these channels. It is much more important to have quality engaging content than constant content.