You can't afford to waste words.
The public everywhere, and in the marketplace in particular, wants good information in as little time as possible. You need to make your point clearly…and get to it fast.

You can't afford to make glaring mistakes.
If readers recognize errors in your communications that they wouldn't make themselves, they lose confidence in you. They need to see you as a knowledgeable, skilled professional.

You can't afford to miss motivating your readers.
The subtleties of style, so easily overlooked or misused by non-professional writers, can be used effectively to capture the interest of prospects and influence clients to respond as you wish. The fact that even best-selling authors rely on good editors is an indication of just how valuable independent review is.