Why do I write this, and who do I write it for? Those are questions that occur to me once in a while, as I suspect they do for many bloggers. I suppose I write it because I like writing about what I do, and would like more people to know something about what I do. If I didn't like doing it I could never keep it up.
As to who I write it for, I think that has to be for anyone I might cross paths with in the course of doing my job. Students, lecturers, and other staff at the Uni mostly, but also other librarians, visitors or people who get lost and wander in by mistake.
That happens in real life too. Mostly they ask where the way out is.