know your reader
One of my favorite books is a book I'll never read. I found it by chance on the shelves of my elderly uncle, once a world authority on fashion history. The cover has a single black and white picture and the title English Laundresses 1850–1930.
That’s it. That’s the book. It's a history about the women who did the washing in England in the 19th and early 20th centuries.
If you thought there was nothing to say you'd be wrong. It’s quite a thick book. No-one knows more about English laundresses than the author, Patricia E. Malcolmson.
I love the fact that such a book exists.
Few people will ever read it. But those who do read it will love it, because it's the only book in the world where they can get the information it contains. It holds a lifetime of wisdom.
Which goes to show that it’s far more important to write the right book for *your* audience than the right book for anyone else’s audience. The right book will always find readers if you know who your audience are.
A book for everyone ends up being read by no-one.