Many new authors, whether they intend to self-publish or follow a traditional route, will ask why they need an editor. Those intending to submit to a publisher may assume edits will happen once they've signed a contract. The self-publishers may consider they have good grammar anyway and want to save on their production costs. The truth is, all writers need an editor, and here's why....
If you are planning to submit your work to a small press (or indeed an agent or a larger publishing house) you may think editing prior to submission is unnecessary, since the work will be edited once picked up. However, you could be doing yourself a great disservice. Publishers know they will edit a work themselves; nevertheless, if it comes down to choosing between two good stories, one of which is well edited while the other needs a lot of work, which do you suppose they will select? In having your story properly edited before you submit, you are giving yourself the best possible chance of acceptance.
With self-publishing, an author will always have an eye on their overheads, and editing can be one of the larger expenses. Some authors may think an outside edit unnecessary, since they have excellent grammar and spelling already. However, I can speak from experience in saying that you never spot your own mistakes. I am an editor and an author. As such, any edits I receive tend to be light. Nonetheless, the editor always finds something. No matter how good your eye, when it comes to your own writing, you are too close to it and you end up reading what you expect to see, not what's truly on the page. A self-published author needs to put out their best work, and a book filled with typos is not the kind of attention you are after if you want to succeed.
A round of edits with an experienced editor is never money wasted and it should form an automatic part of your publishing schedule. I will expand on this topic further in a video later this month, so keep an eye out for that both here and on YouTube. Join me again next month, too, when I will continue this discussion by looking at how you go about finding a good editor.