Another frenzied Black Friday/Cyber Monday season has come and gone, and to the senders who properly prepared and executed their email marketing strategy go the spoils of record revenue (and probably a grey hair or two in the process).

As with any foundational marketing event, it is important to learn as much as possible with the data you have so you can learn and prepare for the next holiday season. So what did we see on our end at SendGrid? What confirmed our suspicions? And just as importantly, what challenged our assumptions and theories? Let’s dig into email data sent through SendGrid this Black Friday and Cyber Monday.

How many words should your subject line be?

What is the first thing a customer sees when you send them an email campaign? Provided you have good deliverability, which is obviously near and dear to my heart, it’s going to be the subject line.

In efforts to stand out, I’ve seen lots of senders have started writing longer and longer subject lines. In fact, the average subject line length is up to 8.1 words over 7.4 from 2016.

For example: “Hey Seth, check out the newest Broncos t-shirts like the ones you looked at last month and also are less than they were.” (The Broncos are terrible this year, by the way…so, I’M thrilled…)

Here at SendGrid, we found that the most popular subject lines for English language subject lines were 7 words, which would have gotten me to something like, “Seth, newest Broncos t-shirts now for less.”

Shorter subject lines actually tended to have better recipient engagement.

Subject lines with just 4 words correlated with the highest engagement–with decreasing unique open rates as the word count progresses to 7.

The takeaway here is that shorter is better. Sure, personalize if you can, but get to the point.

Recipients are as versed in speed-reading emails while deciding which messages to read as senders are at blowing up their inbox. So seven words?! Ain’t nobody got time for that!

For more advice on crafting the perfect subject line year-round, read up on Email Marketing Subject Line Dos and Don’ts.

Mentioning Black Friday in subject lines

We know that space is of a premium, so if you want recipients to know that this is a serious sale, throw “Black Friday” and “Cyber Monday” around, right? “Cyber Monday deal starts NOW!” Wrong.

We actually found that mentioning Black Friday or Cyber Monday in the subject was consistent with lower engagement.

Around 18% of subject lines mention one or the other, although that is up from 11% last year. When the phrases were used, the rate of unique opens were over 5 points below subject lines that made no explicit mention of them. So use this as an excuse to get creative!

Test subject line elements that engage best with your users throughout the year and USE them during this time!

Using discount phrases in subject lines

At its core, what is Black Friday and Cyber Monday known for? Steep discounts. Deals. Percent-off arms race. However, in perhaps the most interesting of the data points that we uncovered, we actually found that campaigns that made no mention of a percentage off out-performed those that did, by no small margin–up to a 6% difference.

Is this because throwing “percent off” messaging is starting to feel spammy to recipients? Hard to tell. Maybe recipients are expecting more and more that senders know their preferences and what they’re interested in. Maybe they get so much messaging like that during this time that they blend together?

Additionally, the rate of senders who include a “percent discount” in the subject line almost doubled from 2016, up to 15% from 8% in 2016. And 20% was the most common discount offered to recipient lists. So if you’re compelled to articulate a percent off, maybe make it an “odd” amount that will stand out?

The interesting takeaway here is that providing aggressive discounts may not be very persuasive for a recipient to open an email from you.

Some other interesting insight from our data includes:

  • Subject lines with “soon” had 19% unique open rates while “now” had 15%
  • “Tomorrow” saw an 18% unique open rate and
  • Subject lines that used the word “today” had 15%

We think these phrasing nuances could be an indicator of how crowded inboxes are and just how much time recipients think they have to take advantage of promotions. It makes sense, if you think about all of the hourly-type sales that happen during this time (I’m looking at you, Amazon Prime…).

It’s very possible that users think that if they don’t see those messages quickly enough after they were sent that they pass on viewing them at all. When the messaging is slightly less urgent, recipients think they might still be able to benefit from the content. So, unless you truly have an extremely time-sensitive promotion, ease up on the urgency.

Emojis in subject lines

Heart, fire, winky face, star. Only a small minority of senders actually still use them (about 3.6%) and when they do, there is a pretty significant drop in corresponding unique opens—up to about 2% compared to, you know, words.

Now, I don’t want to come across as preachy, or worse, bossy. So, if you’ve tested emojis with your recipients and find they react positively, go nuts. But I am of the opinion that if you’re in front of your customers with your message, you should use that opportunity to communicate the value of the campaign they’re viewing and not that you think the sale is “fire.”

Lay off the !!!!!

Finally, subject line punctuation is important (see: “Let’s eat, Grandma.” v “Let’s eat Grandma.”). And what punctuation mark would be better than an exclamation point to communicate an exciting and urgent sale message? Not using any all, actually. But in 2017, marketers were using them more and more.

In the months leading up to Black Friday this year, senders were around 50% more likely to use an exclamation point than last year!

Irony noted, but that is a huge increase. In September of this year, about 21% of subject lines contained an exclamation point, and that rose to 31% during the week of Black Friday.

The result? Email messages that had them saw more than a 2% difference in unique open rate v. subject lines without them (14.0% vs. 16.2%).

Takeaways

So, what does this all mean? In a nutshell, know your customers. Marketers need to know what, how, when, and how often to send to their customers. The only tried and true way to accomplish this is to test and iterate upon your strategy based on your results.

Want to talk more about your own email data? We do too! And If you’re interested in learning more about testing strategies, check out Your Top A/B Questions, Answered. Happy holidays and happy sending!



Seth Charles
An email nerd at heart, Seth has been working in the deliverability and marketing space for six years. He loves solving problems, helping educate SendGrid's customers, and being a part of the email community. As a sixth-generation Coloradan, he always enjoys being outside (especially if it means getting a round of golf in), and thinks John Elway should be the Emperor of Colorado.