I've been asked by a number of writers aiming for a publication deal about editing and re-writing. How many times? How much? Does it change or affect the story as I originally envisioned it? Is the book better after all the hard work? Are you sometimes against the changes and can you refuse to do them?
To answer all these would be a book in itself, but let it just be said that re-writing can only make the book better. Editors are editors for the very reason that they know what works and what doesn't. They know what sells. To ignore an editor's advice is detrimental to the books success, and if that means re-writing and re-envisioning your work then so be it. There will be people who disagree with my sentiment - which is fine - because we all have moments of selfishness where we want to keep the book all to ourselves (me as much as anyone). The problem with that is that it won't sell.
I've just had feedback from my editor on book 3. I'm going to be doing a re-write. It's going to have a huge impact on the book, but I can't find anything that I disagree with. In fact, the suggestions will make the book bigger and better, and will make the ongoing story arch so much stronger and offer further story lines in the future. So what if I have to write a further 30,000 - 40,000 words: that's what I do.
When the book comes out, you won't know how it originally stood. I'll have the memories, so I can pander to my selfish side as often as I want to.