I'm thinking about the case where you have a cache between you and the server, shared by multiple users. I imagine this is useful at facebook, for example for

I'm thinking about the case where you have a cache between you and the server, shared by multiple users. I imagine this is useful at facebook, for example for loading parts of public peoples pages, etc. You are right, that if the data is only used by you, you can just have an advanced cache in the client, sorting it out for you.