Email Frequency and Secondary Clicks
Many email marketers measure their success by open rate. But what determines the open rate? Essentially it's the interest that recipients have in the content being delivered to them. It's always been assumed by some that there's a relationship between email frequency and open rate — by overmailing you turn people off and they fail to open your emails. But this, in fact, might not be true.
To get to the bottom of the situation, I analyzed 213 email marketers who collectively sent 2,075,466,666 emails per month to 414,947,422 subscribers (an average of five emails per month per household). The frequency varied from 0.018 emails per subscriber — a fraction of one email per month — to a high of 48 emails per household in a month. (See chart 1 in the photo box.)
There's a risk in using open rate as an indication of interest in an email campaign — if a subscriber uses a reading pane (as most email subscribers do), as they move down the inbox each reading pane sends back a message to the marketer that this particular email has been opened even if the subscriber may not have really looked at the email at all. Therefore, you have to take email open rates with a grain of salt. If the conventional wisdom is correct, those who mailed more than several times a week should have lower open rates than those who mailed only a few times a month.
But our research didn't bear that wisdom out. The open rates varied all over the lot, as shown in the second graph in the photo box.
The answer to the effect of frequency on open rates has to lie somewhere else. It must be the content of emails that determines the effectiveness of their message. Content is measured by relevance to the recipient. Some marketers have gone to great lengths to try to define relevance. e-Dialog, for example, has six factors that it uses to score relevance. They are: