This guy libraries.

Also trolls.

All I was trying to point out is that there are uses for Pinterest, because I too used to wonder why people used it.

Then I saw my wife use it for inspiration for room decor and fashion design (she's been in the business for twenty years and trained classically, and can basically make anything involving fabric, from a tie to cashmere to drapes), and I gave it a shot. I've used it ever since to show cover artists concepts that I like. That's all. And other genre writers do the same. And all of us have successful businesses.

The point is, like any tool, if you know how to use it properly or what to use it for, you can find benefit from doing so. It is most useful for getting inspiration and then going from there, or for putting together boards that have ideas that work together, so you can convey something to someone in an easy way.