Just a few reasons:

• You know very well what you want to say, but find it difficult to set down your ideas in clear and flowing text.
• You have become so engrossed in your work that you feel you are too close to it to be able to focus on small errors in the detail.
• Maybe English is not your first language, and you need help because of that. Writing in a foreign language is no small undertaking, after all.
• Or maybe you just want to be sure that your work is the very best that it can be.

• What does editing involve? →