No matter how much time you spend working and polishing your novel before you publish it, there will be errors.
They can range from anything from typos and spelling errors to continuity mistakes or word choice errors. Even in the most polished and reviewed books – including those professionally published by one of the big publishing houses – will contain a few errors.
Depending on what the error is (the wrong character name used versus a forgotten comma or two) will depend on if you want to update your already published novel. And there are other reasons you may decide to do an update.
Perhaps you rushed to publish the book and your realized you needed a stronger conclusion, or you should have added a prologue (or want to take out the one you wrote). Many new authors do rush to publish and there is nothing wrong with admitting you made a mistake and wanting to fix it.
Also, you may not have added back matter such as adding a sample chapter and now wish to do that. Or perhaps you want to update the list of other books you have written.
As you can see there are many reasons you want to update an already published e-book. And luckily, it is easy to do that.
Amazon
It is simple to update a book on Amazon, just upload the revised file. It will typically be available in a few hours but could take as long as 48 hours.
Readers who have already downloaded the old version can update to the new version if they sign in to Amazon and download the new file. If your revisions are significant (beyond just a few typos) such as new material, you can send a message to Amazon KDP support and request all readers receive an update. In that case, Amazon will email all owners and let them know about the update.
Smashwords
To update a book in Smashwords, begin at the dashboard and select upload a new version. The book will need to be manually reviewed by Smashwords before it will be included in the Premier Catalog. In other words, until it has been approved, the new version will not show up at Barnes & Noble, the Kobo Store, iTunes or any of the other Smashwords retailers.
Just because you can update your work doesn’t mean that you should (or must). You need to weigh whether it is worth it. If you publish 10 books after your first one, then yes, it might be time to update your back matter on your first published book. If you are only doing it to correct a handful of punctuation or a misspelling or two, then it might now be worth the effort.
Into Another World 