You may think whether you choose to add an epilogue depends on your story. To a great degree, it does, but it’s also a marketing decision as important as a good cover, a well-written book description, and professional editing. It applies to all novels, but first, let’s consider that you might develop the book into a series.

Many authors add a chapter, sometimes ten percent of the next book at the end of the first, doing the same with each as they’re published. The idea is that readers who have enjoyed book 1 may go on and buy book 2. The flaw with that technique is if your novel is properly rounded-off just before “The End” readers will be happy and unlikely to read a sample, especially if they have a long TBR (to be read) list.

Using a short epilogue, not an additional chapter, can still leave the reader happy and ready to click on a five-star rating, but also leave them curious – likely to follow you on Amazon so they get an email when book 2 goes live, and so on throughout your series. By the way, the request to rate on Amazon doesn’t appear where you have typed “the end”, but at the real end, after the chapter or chapters, many never read. Few people take the trouble to write a review, but if they read the whole story there’s a fair chance of a good rating if all it takes is a click on their eReader.

So, what makes a good epilogue?

It arouses curiosity – what might happen if…?

It can establish the next “problem” the characters face without spoiling “the end”.

In a standalone novel, an epilogue can tie up loose ends, but beware. A heroine dreading undergoing IVF for the child she and her partner long for discovering she is pregnant would be great. The reader doesn’t need to know if Auntie finished her quilt.

Book 1 in my first series involved the seduction of a father who’d been away on concert tours while his daughter was growing up. To her, he was a superstar, not a relation within the forbidden degree. She had his child, and the story ended with the baby being a gift to her pregnant mother,  – the children to be brought up as twins. The daughter left the West End for Broadway and a new life.

Book 2 opened with the superstar inviting his daughter to join him on a European concert tour to publicize music written by a younger brother she’d never met but felt she owed her help. Eventually, the father discovered the girl was being blackmailed by a man she’d rejected who’d guessed the truth.

Which would you rather read at the end of book 1 – a chapter showing the girl’s arrival in Paris, or an epilogue that hinted her secret might not be safe? Written from the point of view of the villain, who appeared in book 1 but only as observed by other people, it could be a powerful hook to that “follow the author on Amazon” invitation.