Is the magic width for emailed marketing campaigns thinner than we think?

Is the magic width for emailed marketing campaigns thinner than we think? This morning I got a personal (i.e. not a marketing broadcast) email from long-time Net marketing guru Ken McCarthy and noticed he does something that a few other of the smartest online marketers I know do, he sets his text letter charactor width at 50.



The general rule of thumb for text-message width (as opposed to HTML) is to have your break at 60 or 65 charactors. This means when you're writing in Word and set your typeface to Courier 10 point, your right hand margin will be at about 5 1/2 inches. If it's any further over, you'll get weird line breaks when you put your message into the text of an email message and send it out.



The text-line length rule most people use for their newsletters, their autoresponder messages, and their broadcast marketing campaigns sent in text, is determined by what email technology will do. Not by what's best for the human beings reading your message.



Studies by the newspaper industry years before the Internet came along showed that people have a much easier time reading when articles are in thin columns. That's why you don't get newspapers with stories running the width of the page. Readability.



My question today is, do the old Net marketing gurus know something we don't know about readability and text-messages? (Heck this might also affect your HTML message, because it's about width of copy columns.)