We released the first Black Friday & Cyber Monday by the Numbers round-up eight years ago. The idea was twofold: assess how Twilio Sendgrid managed the increased traffic during the holiday season, and examine the trends and patterns that can massively affect the bottom line of senders that put all of their eggs into this one holiday basket.
In 2016, SendGrid processed a whopping 1.6 billion emails on Black Friday on behalf of customers. We patted ourselves on the back for the record volume, celebrated the fact there were no incidents, and immediately began planning for next year’s event. That’s been the tradition of every Cyber Week since we first noticed the peaks and valleys that demarcate the holiday sending weekend from the rest of the year in our data.
Eight years later, we’ve hit double digits billions in sending per day.
Each year, the holiday shopping weekend gets bigger and bigger. What started as a retail event in the U.S. has grown into something of an international shopping holiday. Retailers from around the world have joined the call to arms of deep discounts, doorbuster deals, limited quantities, and time-sensitive sales to drive home their bottom lines.
This year, Twilio SendGrid processed over 65.5 billion emails during the holiday week starting on the morning of Tuesday, November 26, and ending on the night of Monday, December 2. That’s a 15.6% growth in overall holiday week volume year-over-year.
Double digit growth continued on Black Friday during which Twilio SendGrid processed just over 12 billion emails in a single day, a 13.5% year-over-year growth. On Cyber Monday, Twilio SendGrid processed 11.7 billion emails, which represents a 14.2% year-over-year growth.
Data shows that Black Friday has definitely been the higher volume day. In years past, Cyber Monday eclipsed Black Friday in terms of total sending volume. Is Cyber Monday’s star declining? Probably not. It’s still a very close race between the two days, and now with Giving Tuesday, perhaps we will have a third horse to track over time.
Historically, Black Friday has been the higher-volume day, with only a few years of deviation. Two factors may be contributing to a surge in Black Friday volume: more in-store retailers are curtailing their Black Friday hours, leading to more online specials that compete with Cyber Monday and there are fewer physical retailers today than in past years due to the COVID-19 pandemic. It is also important to note that while Giving Tuesday has been around for many years, it is only in recent years that we have seen marketing adoption for that event.
During Black Friday, Twilio SendGrid’s platform peaked at nearly 1 billion emails per hour. The busiest hour for sending on Black Friday was 9 a.m. EST, and on Cyber Monday it was 12 p.m EST. Although email is a near-real-time channel, busy sending times do not necessarily correlate with peak open times.
Let’s face it, while marketers are sending emails, their recipients are cooking, watching football, and going about their lives as their inboxes fill up with email. For the most part, peak opens follow within the hour after the send. On Black Friday we saw the highest number of opens happen at 10 a.m. EST. However, on Cyber Monday, peak opens took place at 11 a.m. EST.
When SendGrid first started there was no concept of holiday sending. The growth rate was a flat line, but as our customers realized that an API-based mail transfer agent (MTA) could deliver email for more than just transactional use cases, the holiday peaks and valleys began to manifest and reveal SendGrid’s scalable architecture.
Looking back at the entire month of November, we see the continued growth of both the holiday week and overall volumes. Sending volumes spiked, setting new standards day-over-day, let alone year-over-year!
But volume alone isn’t enough. At Twilio SendGrid, volume goes hand in hand with throughput and light speed processing. Twilio SendGrid built our platform to handle large volumes of mail as quickly as possible to ensure that urgent communications reach recipients without being bogged down or getting stuck in lengthy queues.
Our median end-to-end time during the holiday sending season was 2.935 seconds. What does this mean for our senders, and more importantly, their customers? It means order confirmations arrive as quickly as mailbox providers can accept the mail. It also means password resets happen as intended and every other use case of mail is sent and delivered on time, all the time.
Contrary to popular belief, mailbox providers do not erect higher walls or create booby traps ahead of Black Friday and Cyber Monday. Nope, it’s still the same mailbox with the same filters and the same requirements that mail be sent with an understanding of best practices.
What changes is the behavior of senders who look at this time of year as a free pass, becoming over-zealous in their marketing approach and assuming everyone wants to get three emails an hour announcing their time-sensitive deals. Let me reiterate this: the inbox hasn’t changed, but deviation from sending norms and a rational approach to breeding engagement will change the outcomes that senders are trying to achieve.
Our partner, Inbox Monster, provides tools to help senders measure their efficacy. They looked at inbox placement across industry verticals from November 27 to December 3 and determined an average inbox placement of 91.09%.
“While each of the four major mailbox providers contributed to the lift in overall inbox placement rates during Cyber Week, Outlook contributed the most, improving from 80% (previous 90 days) to 89% inbox placement throughout Cyber Week. Over this past year, Microsoft has proven to be a more challenging ISP for most senders to land in the inbox consistently, so this is a nice boost for many to see during Cyber Week. It’s likely that both sender best practices and seasonal engagement trends from recipients contributed to this lift.”
Brad Van der Woerd, Head of Customer Success, Inbox Monster
This is an improvement over the commonly assumed inbox placement rate of 80-85%, which has been a historic high water mark. When the team at Inbox Monster compared the holiday week inbox rate to those of the preceding 90 days, they saw an average increase of 3%. This suggests strong engagement and the proliferation of best practices which shaped better campaigns to deliver on email’s core tenant: email that people want to receive.
Now that we’re clear that the inbox does not change into a high-walled fortress during the holidays, let's examine where the email went during this period of time.
This chart shouldn’t be surprising. SendGrid's data showed that most of the mail we processed heading for Google followed by Yahoo and Microsoft. Gmail has been the dominant player in the email ecosystem for many years. More recently, Gmail compelled the industry to evolve by requiring DMARC as a requisite part of every sending domain. Gmail wants the industry to become more secure through the application of existing email authentication standards. Let’s face it–more secure sending domains create more trust–which leads to less fraud–and can drive better outcomes for senders and recipients alike.
They say you only get one chance to make a first impression—subject lines are literally just that. The first thing a recipient sees on their mobile device is who sent them an email and the subject line. Those two smatterings of letters, numbers, and emojis have a lot of heavy lifting to do. They have to identify the sender, convey urgency while remaining relevant, and help the recipient take the first step on the conversion journey: opening the email.
The most popular subject line length by character count was 39. As a matter of fact, 30 to 39 seemed to be the most popular subject line lengths by character count with steep drop-offs as you dipped into the 20s or climbed up to the 40s. We decided to go a step further and look at the correlation between length and open percentages.
The correlation somewhat follows the volumetric analysis of subject lines processed. What does this suggest? It’s less about the length of your subject lines and more about what you are trying to say, who you are saying it to, and if what you’re saying is relevant enough for them to open your email to engage with the content within.
Characters are great, but very few of us count white spaces and periods. Let’s face it–we’re human. We think in terms of words. So we looked at the same breakdown in terms of the number of words in subject lines.
Lucky number 7 came out on top. When we analyzed engagement by subject line word counts, we get a rather different story.
It appears that pithy subject lines are once again in vogue, thus delivering on the promise that less is more. However, at the end of the day, what really matters is engagement and relevancy. If you can deliver those two things in three words–bravo!
What analysis of subject lines wouldn’t be complete without a deep dive into the pictographic world of emojis? Well, none, to be perfectly blunt.
We took a look at the incredibly long list of emojis that decorated subject lines. In some cases, there were more emojis than actual words. We all know a picture is worth a thousand words. So, without further adieu, here are the top 10 most popular emojis of this year’s sending:
We've come a long way since our first Black Friday & Cyber Monday round-up eight years ago! Back then, processing 1.6 billion emails per day felt like a huge achievement. Fast forward to today, and we continue to shatter records by sending double-digit billions of emails per day!
It's not just about sending more emails, it's about sending better emails—ones that resonate, engage, and convert.
As we look ahead, we're excited to keep pushing boundaries, breaking records, and helping you connect with your audience in meaningful ways. The holiday shopping season keeps getting bigger, and SendGrid is geared up to make next year even more spectacular.
Here's to the power of great emails and the success they bring. Until next year, keep those subject lines sharp and those emojis popping! 🥂
