Are cliffhanger chapters acceptable?

I'm pleased to say that I have just published the fourth in my Stephen Capel murder mysteries, A Twisted Harmony , and I've done something I never thought I would: at the end of the book, I've tagged on the first chapter of the follow-up novel An End to Innocence, which will be published in the autumn of 2017.

When I read a book and hit one of these 'bonus' chapters at the end, I tend to feel a little cheated. This is because I rarely bother to read them, so it feels like the book is shorter than it appeared to be. And the reason I don't read them is because I don't like books to leave things dangling. Inevitably, reading just the first chapter of a book leaves the reader in suspense, potentially for a long time. (It's that US habit of ending a TV series on a cliffhanger until next season.)

I made the decision to do it this time for two reasons. One is that I already really liked the way the new book was shaping up in my mind, so I wanted to get started on it straight away. And the second is that the new book continues straight on from A Twisted Harmony without any break.

So, in essence, A Twisted Harmony has two endings. You can stop reading at the conventional end of the book, where you get a nice, tied-up-loose-ends finish. Or you can continue to the bonus chapter and get yourself into cliffhanger territory. The choice is the reader's. And that, I hope, makes all the difference.