With Holiday shopping kicked off and in full swing, Marigold Engage by Sailthru continued to dig into our data on subject lines from emails sent last year to determine how specific words, characters, and combinations impact email performance during the holidays. The following recommendations come from a sample of 89,932 subject lines for emails sent by Sailthru customers during the 2015 holiday season. In particular, these findings come from a subset of those emails specifically referencing Christmas or the December Holidays.

1. Holiday Specificity May Make a Big Difference

Retailer emails that used “Christmas” in the subject line averaged open rates 26% higher than emails with subject lines that used the word “Holiday” or “Holidays” (without also mentioning “Christmas”). Subject lines mentioning “Chanukah” (or variant spellings) were much less common, but averaged higher open rates still (40% higher open rates than “Holidays”).

2. Leave out Prices and Percentages, Particularly “Extra” Savings

Christmas emails with a price in the subject line were on average 9% less likely to be opened (open rate index 91), and likewise for emails with a percentage in the subject line (typically represented as “XX% Off!”), which were 9% less likely to be opened. Unlike with Black Friday and Cyber Monday subject lines however, there was no clear relationship between specific discount numbers and open rate performance. Emails mentioning an “Extra” percentage discount in the subject line performed particularly poorly, averaging open rates 24% lower than the retail average.


3. Don’t Worry About the Length

Like the results from our Black Friday and Cyber Monday analysis, data from our sample suggests that there’s little correlation between the length of a subject line in words and the open rates when it comes to Christmas emails. In fact, our data suggests that longer subject lines—12-16 words—may in fact perform better overall.


4. Likewise for the Words — Shorter Isn’t Necessarily Better

Similarly, performance results varied greatly based on the average length of words used in subject lines. As such, don’t worry about using shorter words in your subject lines, and generally be as verbose as you need to be to get the message across, within reason.


5. Curb Your Enthusiasm

You may be full of holiday cheer, but retail emails with an exclamation mark in the subject line tended to average slightly lower open rates than the category average (Open Rate Index 70), as did subject lines written in ALL CAPS (Index 86). Comparatively, subject lines containing some 1-2 words in ALL CAPS averaged higher open rates (Index 105).

6. The Terms of Holiday Endearment 

Here are some of the most commonly-used terms in Christmas and Holiday emails, and how they affected open rate performance vs. the baseline.


BONUS 7th PROTIP: Special Characters are OK, Performance-Wise

Emails with subject lines that contained unicode special characters or emoji such as ☺, ④, or → performed slightly better than average in terms of open rates (open rate index 117).


Should any of these recommendations fly in the face of conventional wisdom within your organization, we’re here to help! With billions of emails about to be sent this holiday season, and billions of online commerce dollars at stake, marketers will be pulling out all of the stops to climb to the top of the inbox, and climb over your email! Ecommerce and retail professionals should at minimum earmark 10 – 20% of their holiday marketing programs to test the recommendations outlined above, and expand the test based on the results. Happy Christmahanakwansika from all of us at Sailthru.