Our analysis of 229 million BFCM emails shows that less is more

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The Black Friday-Cyber Monday mega sales weekend, known as BFCM or Cyber 5, is increasingly popular for customers—but also increasingly difficult for merchants.

In 2021, Shopify store owners made a whopping $6.3 billion in sales between Black Friday and Cyber Monday. This is up from $5.1 billion in 2020 (a 24% increase) and $2.9 billion during BFCM 2019 (an amazing 76% increase) in sales worldwide.

The reasons are plenty—better ecommerce adoption worldwide, with the pandemic a significant factor, more stores, more products, more ads, etc.

But with more sales, we’re getting more competition, with mega outlets like Amazon adding more niche products to their lineup and taking up a bigger piece of the pie. That leaves smaller ecommerce businesses having to fight harder to get noticed by their customers.

Since email marketing is one of the best sales channels, we decided to see what kind of email elements—images, buttons, words, subject lines, etc.—lead to the highest engagement and, most importantly, sales.

This will help merchants to incorporate these high-converting elements into their newsletters and watch their email marketing sales 🚀

Want to learn how to boost your sales for Black Friday? Check out Omnisend's BFCM Hub for helpful articles, videos, podcasts, reports, and so much more.


In order to assess the highest-converting and most popular elements of our customers’ BFCM newsletters, we analyzed more than 229 million emails (from 40,283 total campaigns) sent from November 25 - December 2, 2020.

In order to look at the most popular, we used various filters to remove outliers and extremely poorly performing brands (or, most likely, “testing” campaigns) that would skew the results.

Once filtered, we used word and word phrase frequency calculations, and took averages of campaigns or brand campaign averages.

We used boxplots to plot various elements against their respective open and/or click rates.

Key takeaways

These are the main results:

  • Subject lines that have up to 7 words have better open rates
  • Emails containing up to 480 words have higher click rates
  • Emails with 2-3 CTAs show the best click rates . Emails with more than 3 CTAs have lower click rates
  • Adding 6 products to your email seems to be the sweet spot for higher click rates, but adding up to 3 also shows good rates
  • Generally, discounts offering 10%-25% off show better click rates than lower or higher % discounts
  • “Thanksgiving,” while a less popular word to use in subject lines , has the highest open rates compared to the other BFCM days . However, we'd still recommend using "Black Friday" or "Cyber Monday" in your subject lines
  • The phrases “chance to save” and “coupon” have better open rates than “free shipping” or “BOGO” when used in subject lines

Below is an infographic that summarizes our key takeaways:

You can get the full-sized infographic here

Comparing text length to open and click rates

One of the first steps our research took was to see how word count relates to open rates (for subject lines) and click rates (for email content).

Subject line length

If you’ve ever used our Subject Line Tester , you’ll have seen this recommendation to use between 4-6 words (or 21-40 characters). Anything longer than that, and you’ll have seen this message:

So how accurate is this? What does our new data show?

Subject lines up to about 7 words have the best open rates, ranging from 15%-17%. Anything more than that begins to drop steadily.

One important note: as you can see, 0-3 words seems to offer the best open rates. However, because it is so unpopular (with only 2.5 million emails sent vs. the 61 million sent with 5-7 words in the subject line), you should take this open rate with a grain of salt.

The most popular word count for subject lines seems to be between 5-7 words, as more than 61 million emails were sent with subject line word counts in this range.

The second-most popular length is for 8-10 words, which still have a respectable 14.6% average open rate. The lowest open rate is for subject lines with 16 or more words (13.8%).

Email content length

Getting your contacts to open the email is one task, but convincing them to click on a product to purchase or at least learn more is another task. Should you be more descriptive, and use more words, to sell your products? Or is less better?

The data seems clear: newsletters containing up to 160 words seem to have the best click rates.

The second-best grouping is for newsletters containing between 160-480 words, which is also the most popular word count for all emails sent. After 500 words, the click rate begins to drop steadily.

One interesting note: there seems to be a spike in click rates for emails with more than 560 words. However, because of the low number of emails sent that have these word counts, this is most likely noise and therefore its significance decreases.

How many CTAs and products to list?

At this point, we’re starting to see a trend: the more you use, the less you get. We’re seeing this when we analyze the number of newsletter elements used—such as CTAs/buttons, products listed, and images—compared to their click rates.

Let’s look at these in turn.


It’s a general newsletter design best practice to not include too many CTAs. Generally, have one main CTA and you can have supporting CTAs to either similar products or educational content, with no more than 3 CTAs.

But what does the BFCM data show?

It seems to hold. 2-3 CTAs show the best click rates, with newsletters containing more than 3 CTAs quickly dropping in click rates. The second best click rates belong to 0-1 CTAs, which also happens to be the most popular number of CTAs in the newsletters we analyzed.

FYI : don’t complicate your copy for your CTAs. Our data shows that using the classic “shop now” is both the most popular and has one of the best click rates (2.23%):

The less popular “shop black friday” CTA has an even higher click rate, coming in at 2.62%. However, due to the comparatively low sample here (only 162 newsletters contained this CTA text compared to the 3292 campaigns using “shop now”), it’s likely that there’s a bit of noise involved in this data.

Having too many options in an email most likely leads to analysis paralysis where your contacts can’t decide between multiple options, and they end up clicking on nothing.

Product listings

When comparing the number of product listings to their click rates, we can see slightly different insights compared to the CTA data from above: instead of fewer being better, we’re seeing that more product listings (up to a point) have slightly better click rates.

Having up to 3 products listed in newsletters shows some good click rates up to 1.94%. When adding 4-5 products, however, this drops to 1.79%, but shoots up to 2.03% when showing off 6-7 products. After that, it drops again.

However, this should be taken with a grain of salt, since the click rates aren't different enough to have conclusive results.

Bigger discounts lead to lower click rates

For most people, it seems obvious that a bigger discount or saving for a product would lead to more people buying the product.

However, our analysis shows that this isn’t necessarily true. In fact, it seems to be quite the opposite.

When looking at the chart of % discounts compared to click rates, we can see that a few trends emerge:

Primarily, it looks like there’s a certain sweet spot, a sort of Goldilocks zone, for which % discount generates better click rates. Generally, 10-25% discounts show better click rates than anything below or above that range—earning between a 2.04%-2.2% average click rate. There’s a pickup of click rates with discounts in the 65%-75% range.

This is quite surprising, since one would expect that an offer for 55% off would fare better than an offer for 30% off.

However, when looking at the most popular % discounts in subject lines, we see that 50% off is the most popular, followed (surprisingly) by 70% off. 30% off is the third-most popular, then 40% off.

Our data shows that those campaigns would have gotten better click rates if they’d use lower discounts.

Key terms in subject lines for higher open rates

One of the first steps our research took was to compare specific key terms to their open rates in subject lines. These terms are grouped according to the following themes, and their purpose of analysis:

  • Days of BFCM: which of the four days, from Thanksgiving to Cyber Monday, showed the best open rates?
  • Terms related to urgency: which terms of urgency are most effective?
  • Terms related to general sales: which descriptive terms have the best effect on readers?
  • Terms related to special offers: what kind of offers entice readers to open their emails?

Let’s look at each grouping in turn.

Days of BFCM

In order to asses which of the BFCM days showed the best open rates, we looked at the following terms:

  • Thanksgiving
  • Black Friday
  • Small Business Saturday
  • Cyber Monday

(Because there’s no official day for the Sunday before Cyber Monday, we decided not to measure that.)

Overall, the results for this particular analysis were not really conclusive. All of the BFCM days, as far as they're used in subject lines, returned similar results (roughly 15% open rate).

In our analysis, two things were immediately (and unsurprisingly) obvious: Black Friday and Cyber Monday were the most popular, with Black Friday almost three times as popular as Cyber Monday.

Secondly, Small Business Saturday was the least popular, and this could be that our ecommerce merchants are by-and-large DTC, and may also not refer to themselves as a “business” but rather a shop or store.

Thanksgiving was also pretty unpopular, roughly 6 times less popular than Cyber Monday and 16 times less popular than Black Friday.

However, in terms of open rates, the lineup changes. Out of these four terms, subject lines that included Thanksgiving had the highest average open rates (15.3%). Small Business Saturday had the second highest average open rates (15%), followed closely by Black Friday (14.9%). Cyber Monday had the lowest average open rates, coming in at 13.8%.

But, as Austin Powers once famously said: “What does it all mean, Basil?”

Do A/B testing ( easy with Omnisend ) to see which subject lines have better open rates. (By the way, you can also use Omnisend’s A/B testing to see which email content, in its entirety, performs better.)

Terms related to urgency

In this group, we wanted to analyze the different terms merchants used to denote urgency. This included the following:

  • Hours left
  • Days left
  • Today
  • Last chance
  • Last day
  • Sale ends
  • Sale starts
  • Miss out

Out of all of these terms, “hours left” had the lowest average open rates, coming in around 12.2%. The highest of these terms is “sale starts” with a 15.5% open rate.

The two most popular terms in this group are “last chance” and “today,” with both having similar open rates, at 14.2% and 13.9%, respectively.

The least popular, in terms of volume, is “days left,” which seems to indicate that merchants are sending out more emails with sales ending within hours, not days. This is backed up by the greater popularity of “last day,” “today,” and “last chance,” which generally have special offerings ending in less than 24 hours.

Terms related to general sales

This grouping aimed to see which of the multiple terms for sales (such as “bargain” or “offer”) showed higher open rates—hinting at the possibility that they are more intriguing for readers.

The terms we looked at were:

  • Sale
  • Deal
  • Bargain
  • VIP access
  • Biggest sale
  • Early access
  • Offer
  • Special
  • Savings
  • Save

This may come as no surprise, but the term “sale” is the most popular when looking at volume. The least popular are “bargain” and “VIP access.” Here it’s important to note that these differences in volumes can affect the open rates.

The highest open rate belongs to the terms “special” and “offer,” coming in at 17.1% and 16.9%, respectively, while the lowest belongs to “savings” (13%). “Early access” also performs well with a 16.2% open rate for each.

So don’t knock the term “sale” in your subject lines. Instead, try to see how it works compared to other higher-performing terms like “special,” “offer” and “deal.”

This could be, for instance, “New deal: take 25% off in our BFCM sale.” See how this subject line performs.

Terms related to special offers

When we talk about special offers, we’re looking at what kinds of discounts, free shippings, gifts, etc., work best to get higher open rates.

These terms include:

  • Special offer
  • Free shipping
  • Use code
  • Coupon
  • % off
  • Chance to save
  • Up to
  • BOGO

So, without looking at the chart, which do you think is more intriguing for subscribers: free shipping or a special offer?

Apparently, “special offer” is more interesting. It’s even better if you use “coupon,” but the best carrot to dangle in front of your customers is the term “chance to save.” This saw a 17.2% average open rate, compared to the 14.3% open rate from “free shipping” or even the 13.3% open rate for the popular “% off” (regardless of the size of the % discount).

More specific special offerings like “BOGO” perform less well, coming in with the lowest average open rate at 12.9%.


Again: “what does it all mean, Basil?”

Let’s look at the some key points and see what our analysis might imply:

  • Subject lines that have up to 7 words have better open rates
  • Emails containing up to 480 words have higher click rates
  • Emails with 2-3 CTAs show the best click rates . Emails with more than 3 CTAs have the lower click rates
  • Adding 6 products to your email seems to be the sweet spot for higher click rates, but adding up to 3 also shows good rates
  • Generally, discounts offering 10%-25% off show better click rates than lower and higher % discounts

Nearly all of these point to a simple trend: after a certain sweet spot, the higher you go, the less you get . The higher your discounts go, the lower your click rate. The more CTAs you have, the worse your email performs. The longer your subject line, the lower your open rate.

The sweet spot here is critical, and it is relatively in the lower range. 2-3 CTAs are best, compared to five or more. 10%-25% off can lead to more clicks than 60%-70% off.

Other key points:

  • “Thanksgiving,” while a less popular word to use in subject lines, has the highest open rates compared to the other BFCM days . However, we'd still recommend using "Black Friday" or "Cyber Monday" in your subject lines
  • Subject lines offering special promotions with longer deadlines are less popular but have higher average open rates
  • It’s more effective to use “special,” “offer” and “early access” in your subject lines than “sale” — but you should most likely use them in combination
  • The phrases “chance to save” and “coupon” have better open rates than “free shipping” or “BOGO” when used in subject lines

When talking about subject lines, the best thing to do is to test it out for yourself . The data here is an average of all campaigns sent over by Omnisend merchants in the BFCM 2020 period and they may not perform the same for you.

For that reason, we usually recommend merchants use A/B testing —send two versions of the subject line to two smaller sections of your subscriber list. The one that performs the best goes to your larger list.

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