I’m sure all of us receive some promotional e-mails with content that just seems to go on forever.

There’s no way that’s accomplishing the company’s marketing and sales goals.

But just what exactly is the right length of content in a promotional e-mail communiqué?

Assuming that “the wisdom of crowds” can get us pretty close to whatever that sweet spot is, looking at findings helpfully collected and aggregated by research firm and direct mail archive Who’s Mailing What! provide some pretty good clues.

WMW! tracks nearly 225 business categories, looking at the word count of e-mail messages deployed by companies active within each of them.

The average e-mail length for nearly all of the categories that WMW! tracks is substantially below 300 words.

[To compare, that’s shorter than the length of this blog post, which is around 300 words.]

And there are very few exceptions – fewer than ten, according to WMW.  In those seven categories, customers and prospects are used to encountering more verbiage in order to remain interested in the message.

The few business categories with the highest average content length (350 or more words on average) turn out to be the following:

• Business/financial magazines
• Newsletters
• Political fundraising
• Religious magazines
• Seminars and conferences
• Social action fundraising
• Special interest magazines

Incidentally, the two categories with the absolutely highest number of words are social action fundraising (nearly 650 words) and seminars/conferences (around 620 words).

… Which for those two categories makes complete sense.  Donor prospects are going to need to read a good deal about a cause before opening their pocketbooks.  And people are going to need details about a seminar’s content and quality before agreeing to pay the typically high fees charged to attend.

But for everyone else, short e-mail promos are clearly the name of the game.  If word counts go much above 200, it’s probably getting a tad too long.