That's for purchases on the net. Even mediocre authors are published quite often. That's because they know what Publishers want or don't want as the case may be. In school you were told how important neatness was. The same thing applies to articles.
Nobody wants to read chopped sentences or mis-spelled words.
Use your spell check if you have one, if you don't then proof read over and again. Use a line ruler to keep your lines at or under 65 characters. Always hit your return key after each sentence. You can't determine how many characters each mailer is set at, only the user does that, and many of them have no idea of how to set it anyway. Publishers are always looking for fill ins.