The Email Wars

Optimal Day of Week for Emailing Now Tough to Choose

An eROI study of emails sent, read and clicked on shows that the market has finally evened out into a sort of stasis where the number of emails sent out on a particular day of the week is only that which won’t overload the reading rate. This has also reduced the volatility of click rates from day to day. The image at left shows this relatively fluid trend of emails sent. A contrasting graph showing fairly large discontinuities from a year ago can be seen in the jump.

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This quarter eROI noticed a nice smooth progression of email sent throughout the week and big drop-offs on the weekend, as expected. Thursday leads the way in email sent but places 4th in email read, Wednesday looks like a nice, even day. Best number of reads, average clicks and high volume.

This goes to show that the “best” day is a moving target, wrapping up the year-long study that validated our hypothesis that it was a fluctuating and ever-changing element and that testing is vital. While this seems like common sense it does show that patterns exist on a macro and micro level and you need to identify those by performing, at minimum, a quarterly audit of the emails you have sent.

Tuesday and Wednesday are the most consistent across the year and Monday and Thursday have been the most volatile on a “reads” perspective for week days. There have been significant drop offs on Friday and Saturday from the first half of last year, but more consistency over the last two quarters.

Consistent general themes we have noticed over the year that we conducted these studies:

Fatigue sets in as the week wears on, people tend to read email less later in the week (B2B)

Tuesday - Thursday are the highest volume days and marketers are staying away from the edges

There is minor variation in click-through rates, it all comes down to how compelling and relevant the offer is and little to do with day.

More importantly, over the year that eROI has been reporting on these numbers, we noticed that open rates across quarters are trending downward. But what does this all mean? Recently ClickZ had reported a consistent theme back on March 15th. Their thoughts are that it is due to the filtering of HTML email by some email programs (e.g., Gmail, Outlook 2003) and therefore the blocking of images (the way ESPs track reads). This is not necessarily new news, but it is something that clients should be aware of that reads is only an indicator. With this in mind, don’t forget to put in a text link at the top of your email that links to a “web version” so you can easily display the email.

* Key take-away
* Click rates stay relatively consistent across quarters. It does not matter if email clients are blocking images or HTML for this as trackable links are completely independent of read tracking. What this is showing, and something we have always preached, read rates are not a true indicator of the success of email. A two-second Outlook preview marks an email as a read. As an industry we need focus more on action (clicks) if we are looking for true measurable data.