When is the best time to send B2B email marketing campaigns?


This was the perfectly reasonable question posed by one of my clients this week. I think my response (in a nutshell, “it depends”) was probably more equivocal than they were hoping for.

Yet, just as I’m deeply suspicious of any blog that tells people what they ‘must’ do in marketing, so I believe that any marketing consultant faced with this question needs to advise his or her client to test different approaches and see which works best for their message and audience.

That is: Test. Measure. Adapt.

I thought it was worth reading around on the subject to compare my experience across a number of sectors with commonly accepted wisdom and wider analysis.

I’m focusing on B2B email campaigns here as that’s my area of interest, but the demarcation between business and consumer audiences for email marketing is increasingly blurred. In one US survey[1] 88% of respondents said they treated their work and personal email boxes as one.

What is success in email marketing campaigns?

What do we mean by success when we’re assessing the optimum time for email campaigns? It’s a fair question and experts agree that while open rates are important (particularly for measuring the effectiveness of your subject line) it’s click through rates (CTRs) and consequent revenue generated, when measurable, that really count.

Received wisdom in email marketing

Of course, we all have some cherished assumptions about the best time to send an email newsletter or campaign; the early mornings of Tuesdays, Wednesdays or Thursdays are most often cited as the optimum periods. Certainly for one of my clients who often uses email campaigns for a global audience, Thursdays outrank every other day of the week tested in terms of open rates and click through rates (CTRs).

By coincidence, my review was given a kick start when I received a newsletter from email marketing software vendor, Vertical Response, this morning. It included an article called The Surprisingly Best Times to Send Your Email Marketing Campaigns. The piece dates back to February this year and refers to data collected in 2012, but still makes some interesting assertions.

Most people now open emails on mobile devices

54% of people now open emails on mobile devices, according to an Experian report quoted in the article, and this has implications not only for email design but for the time of day that an email can have most impact. According to another Experian report, open rates reached an average of nearly 22% for emails sent between 8pm and midnight and a respectable 17.6% for the hours between midnight and 4am.

Emails sent at the weekend, however, showed the highest open rates, CTRs and revenue per email.

Surprising indeed. I wonder how much these figures are skewed by the large number of consumer campaigns included in the overall sample. Even Experian themselves acknowledge: “To optimize results, it is essential to test the best time and day for your individual brand.”

I turned to Dan Zarrella’s book, The Science of Marketing, for further clarity. It may be three years old now, but Dan’s analysis is a good read for anyone interested in digital marketing metrics.

Should I send email marketing campaigns at the weekends?

Zarrella starts by aiming to debunk the assumption that Tuesday is the best day to send emails, if for no other reason than it’s become such a common assumption your message will get drowned out by the noise.

He then provides more support for emails that are sent at the weekends, which in his experiments achieve CTRs that are almost double those achieved during the week.

So it’s worth testing a weekend mailing, but as Zarrella rightly concludes, the challenge is in understanding which messages work better at the weekends.

One assumption that Dan’s work has reinforced is the power of the early morning email. His extensive data set (based on email campaigns sent by thousands of Hubspot customers) show CTRs for emails sent between 6am and 7am that are significantly higher than those sent at any other time of the day. His data too show a slight increase towards the end of the evening.

So far, so simple. Until we look at analysis of even larger sets of data, including input from MailChimp’s Send Time Optimisation System. Given MailChimp mails around 10 billion emails a month on behalf of some 12 million+ users, its data carries a lot of weight.

Coschedule, the marketing scheduling software, helpfully summarised MailChimp’s data with inputs from nine other studies in this post: What 10 Studies Say About The Best Time To Send Email, which promises to nail the answers for good.

I encourage you to read the article in full, but here are the two key headlines, according to Nathan Ellering’s analysis:

Tuesdays are the best days to send emails by far (followed by Thursdays then Wednesdays).

Note: Ellering accepts that there is data that shows weekend emails do well but says, “while the open rates may be higher in general, the actual number of emails opened is way lower.”  If I understand this correctly, his argument is that while my individual campaign might do well, across all industries fewer emails will be opened. Effectively Ellering’s findings reinforce Zarella’s point that emailing when there is less noise will get you noticed.

So don’t discount that weekend experiment.

Mid-morning is the best time to send email campaigns peaking at 10am (followed by late evening).

Citing data from Wordstream, Mailchimp, Customer.io and others, Ellering concludes that not only is 10am the most popular time to send emails (which is one thing) but it also achieves the highest CTRs.

Ellering goes on to provide some great advice on headlines and the issue of HTML vs Plain Text emails, which I’ll look at in a future blog.

Although Ellering’s analysis has led him to conclude that 10am on Tuesday (i.e. the perceived wisdom) is the optimum time to send an email marketing campaign, he rightly advocates testing what works with split tests, Google analytics and other tools. And of course what works best for your e-newsletter might not be the right time for your lead generation email campaign.

One final thought from Dave Chaffey of SmartInsights. Never one to shy away from the complexities of marketing, Dave suggests a near future in which sending times are automatically scheduled for each individual contact on your database according to customer segment and previous behaviour patterns measured in multiple test campaigns.

Or in other words: Test. Measure. Adapt. Individually.
[1] Dan Zarrella, The Science of Marketing, 2013 page 132