Black Friday & Cyber Monday 2018 By The Numbers

December 14, 2018
Written by
Len Shneyder
Opinions expressed by Twilio contributors are their own

Black Friday & Cyber Monday 2018 By The Numbers

The halls are being decked–which means we’re over the Black Friday/Cyber Monday hump, and eagerly awaiting the New Year. So now’s a perfect time to sit back, relax, and review the trends that marked SendGrid’s biggest mailing days of the year and ruminate on how to make the coming holidays even more successful.

The Big Picture

We saw massive email sending volumes on both Black Friday and Cyber Monday that translated to a 43% and 37% year over year growth respectively. The continued focus and increase in holiday sending volume speaks to the power and allure of this time of year as crucial for both the brands that are capitalizing on the excitement that leads up to the holiday shopping season and for the consumers who value the relative deals and savings.

Expressing Excitement

During Black Friday week this year, marketers used fewer exclamation points in their email campaigns!!! Although exclamation point usage was slightly up overall in 2018 over 2017, they were used 12% less during the holidays.

As in 2017, subject lines with exclamation points saw less engagement on average. In 2018, subject lines with exclamation points saw lower engagement (20% unique open rate versus 25% without). The implication here is that we all know what time of year it is, and the visual emphasis isn’t necessarily driving greater consumer response.

Stating The Obvious

As we saw last year subject lines mentioning a shopping holiday tended to perform significantly worse:

Average unique open rates for subject lines:
  • Black Friday: 14%
  • Cyber Monday: 12.5%
  • No Mention in Subject: 25%
What can you do to increase your open rates? It may be worth testing more creative subject lines that either leverage segment specific interests, previous purchase behavior, or deliver a wholly different and unique, if not clever and compelling value proposition.
Simply reminding people isn’t enough.
Every website and commercial they see on TV states the obvious–the holidays are here. Marketers need to work harder to differentiate their message. In 2018, marketers may have learned that less is more and mentioned Black Friday or Cyber Monday less than in 2017 (13%, compared to 18% last year).

Believe it or not, they may just want the mail!

One of the interesting trends we see continuing on Black Friday is the delay between send and time of open. On an average Friday, that delay is in the neighborhood of 4.5 hours, on Black Friday that delay is about 42 minutes shorter. We can infer that either having the day off, or the perception of deals is a stronger driver to re-engage with the inbox.

Not surprisingly, that delay is slightly shorter on a mobile device vs. a desktop.

[caption id="attachment_37047" align="aligncenter" width="825"] *Data is from 2017[/caption]

To Discount Or Not To Discount

Every year marketers have to strike a magic balance between preserving profit margins and driving sales. Consumers, on the other hand, need to suss out what is truly a bargain and where to spend their hard-earned cash.

Discount usage fell to only 6%, below 2016 levels and well below 2017 levels (15%). The data shows that while 20% is still the most popular discount rate (as in 2017), 50% and 30% were almost as popular. The trend we saw in 2017 continued in which subject lines offering discounts tended to see lower engagement (7%, compared to 8% on average).

Although not a huge disparity, it is still surprising to see that the CTA of a discount in a subject line doesn’t have markedly higher engagement.

Make The Case for Right Now

Announcing a discount in the subject line of an email is only one form of creating excitement and urgency—reminding customers that the holiday shopping event is time sensitive is another. Subject lines asking for an action “soon” performed better than subject lines asking urging customers that “now” is the time (25% unique open rate vs 16%).
We found subject lines with urgency performed roughly 50% better in 2018 than in 2017.
Continuing the trend from 2017, subject lines asking for an action “tomorrow” performed better than subjects asking for an action “today” (17% unique open rate vs 16%). Or as I like to think of it, the future reminder is less abrasive than being told what to do.

Being Verbose

Subject lines are your first, and most important, opportunity to get someone’s attention. Trying to express too much in a subject line is problematic as there’s limited screen real estate in most email clients, and that real estate becomes even more precious when you take into account mobile screens.
In 2018,  7 or 8-word subject lines tied for the most popular length in the English language.
In 2017, we also saw 7 as the most popular subject line length, but it was shorter subject lines of 5 and 6 words that followed it vs. the 8-word subject line in 2018.

Making The Right Decision

One striking observation we saw in this year’s behaviors had to do with how people clicked on links in emails. Of those recipients who click on a link in an email sent around Black Friday, 26% will click more than once on links in the same email. This is up from 22% last year.

Consider human patterns: receiving an email during lunch waiting in line to buy your food, you might click the link, load the page or app, but not convert. Later when you have more time you might click the link and convert again. Whatever the reason behind the behavior, one thing is clear: people come back to emails (and a significant number of them).

We also saw that about ⅔’s of the time, the user is clicking separate links. The other ⅓ of the time, the user is clicking the same link multiple times.

We know from past analysis–and the fact that email fatigue is real–that high send frequency can harm deliverability and deteriorate recipient engagement. Combining multiple CTAs may be a viable alternative to separate emails. However, keep in mind the form factor, too many CTAs and your customer will lose interest. Test your emails and segments to determine the right number of CTAs vs deliveries per week.

Striking A Balance

Aside from content, one of the most important decisions any sender can make is how much to send and how often to send it. By analyzing weekly send frequency and percent of recipients reached that week (the total unique recipients engaged that divided by total unique recipients sent to) between September and November 2017, we found that more was truly less.

But as weekly send frequencies increased, we observed diminishing returns in overall engagement.
Increasing send frequency from 1 to 2 emails in a week typically led to 25% more of the list engaging that week.
As senders increased email campaigns from 2 to 3 campaigns in a week, this resulted in a 9% increase in the number of unique engagers. While increasing from 3 to 4 campaigns in a week resulted in just 3% more recipients engaging with 1 or more emails that week.

We can infer from the data that more is not more—and we know for certain that emails resulting in a lack of engagement will drive down a sender’s overall reputation at mailbox providers like Gmail that look for clear signals of engagement.

We observed this same pattern of diminishing returns this year making it as crucial as ever that senders balance the perceived returns of sending more with the potential pitfalls associated with sending so much that it has negative and adverse effects on their overall sending reputation.


Although the havoc and excitement of Black Friday and Cyber Monday are behind, the real job and challenges lie ahead. The holidays are the Superbowl of all the previous campaigns, special events, half-yearly sales, and experiments that senders run throughout the year. Finding the right mix of content, frequency, timing, and offers to drive home the necessary ROI to sustain them until the next holiday cycle really is a year-round job.

Email is a wonderfully instrumented channel that allows us to experiment endlessly and we should all take time out of our day to study not only the results but the experiments that led to those results and prepare a fresh round of tests in the days to come.

For more tips on email marketing experimentation and testing, check out Your Guide to Email A/B Testing and Optimizing your Call to Action.

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