One of the joys of self-publication is that you can do what you want. If you’re hoping for traditional publication, you have to fit into various categories. Your book has to be of a recognisable type so that the bookshops know where to shelve it (so your zombie romance mystery thriller set in the 1660s is going to give them a real headache). It’s helpful if you’re an established author, or a bright young thing, or a local writer- anything that means you can sit comfortably on a shelf with others of your kind. And your book needs to be of a certain size – both dimensionally and in length. If it’s too tall or wide, it won’t fit on the shelf. And if it’s too short, there won’t be enough pages to justify a spine – and without a spine, you’re lost on the shelf.
All of these things matter much less for self-published books – although the zombie romance mystery thriller set in the 1660s is still going to be a hard sell, if only because Amazon will have the same categorisation problems as Waterstones. Crucially- as far as I am concerned – the word-count is entirely up to me. Traditional paperbacks – i.e. ones of the familiar size and weight – are between 80,000 and 120,000 words long. “Fatal Forgery” is going to be about 55,000 words long – but for a print-on-demand paperback, and even more so for an e-book, that matters not one jot. Which means that I can tell the story in exactly the number of words that it requires – not the number that the publisher wants to make the book the right size.