Special Note: This piece has been guest authored by Karolina Petraškienė from Omnisend and it can potentially help a lot of startups improvise their Email marketing campaigns for a better CRO.
When we first looked at our brands’ data from last year, for emails sent throughout 2017, we noticed some surprising things.
Generally, we can put forth the 4 most interesting questions we raised and were able to answer about subject lines, including:
- Does personalization have any effect on open rates?
- Do exclamation marks help or hurt your conversions?
- Should you offer discounts as percentage or dollar amount?
- How long should your email subject lines be?
1. Does personalization have any effect on open rates?
When we talk about personalization, here we mean adding the recipient’s name in the subject line (usually just the first name).
However interesting that may be, we wondered whether personalized subject lines would cause people to open it more or not.
In my opinion, first name subject lines have fallen out of vogue and can even seem spammy (perhaps because they’re unrealistically personalized, since I know it’s a company and I know it’s automated), while my colleagues had differing opinions.
The data was surprising: out of all emails sent, only 3.5% contained a personalized subject lines.
When comparing the average open rates for those, we see that personalized email subject lines have only a 0.2% point increase in open rates (18.1% personalization open rate vs. 17.9% non-personalized open rate), which is not statistically significant.
Therefore, the data seems to show that personalization has no real effect on open rates.
2. Do exclamation marks help or hurt your conversions?
When we compiled our 30 most successful email subject lines for newsletter campaigns, we noticed that 14 out of the top 30 contained an exclamation mark.
We began to wonder if including exclamation marks in subject lines would have any impact on their open rates. We broke this down into the two categories: newsletter campaigns and automated email workflows.
A. Campaigns
For regular newsletter campaigns, 42% of all emails sent had subject lines with exclamation marks, and 58% had none.
We saw that subject lines without exclamation marks had an 18% open rate vs. 17% for subject lines with exclamation marks—a full percentage point better open rate on average.
We broke it down further to the amount of subject lines: the more exclamation marks, the lower your open rate will likely be. Average open rates for subject lines with 1 exclamation mark is 17.5%. It goes down to 16.7% for 2 exclamation marks, and finally 16.5% for 3 or more exclamation marks.
B. Automation workflows
95% of all automated emails that Omnisend marketers send out contain exclamation marks. That is one marked difference between automation and newsletter campaigns.
In total, automated email subject lines with 1 exclamation mark have an open rate of 29%, while 2 or more raises that open rate to 35%.
However, we have to take these numbers with a grain of salt, seeing as there is a big difference between the amount of subject lines with 1 exclamation mark vs. those with 2 or more.
We saw some other interesting results when we broke it down into single-email automation workflows vs. workflows containing a series of emails.
Automation, 1 email: Automation emails with 1 exclamation mark had a 47% open rate, but only a 42% open rate for 2 or more exclamation marks.
Therefore, this data suggests that for single-email automation workflows, 2+ exclamation marks in your subject lines will have a positive effect on your open rates.
Grain of salt: the amount of subject lines with 2+ exclamation marks are about 0.7% of those subject lines with exclamation marks.
Automation, series: Automation emails with 1 exclamation mark had an open rate of 24%. However, this time 2 or more exclamation marks have a negative effect on open rates, as those result in only a 21% open rate on average.
Therefore, when you have a series of emails in your automation workflow, 2+ exclamation marks will bring down your open rates.
3. Should you offer discounts as percentage or dollar amount?
One big question we often get here at Omnisend is whether it’s better to give a discount as a dollar amount (get $15 off) or as a percentage (take 10% off).
We decided to look at the data to see how open rates differ for subject lines containing the dollar ($) sign vs. those that contain the percentage (%) sign.
10x as many marketers used the % sign in their subject lines vs. those that used the $ sign. Nonetheless, the $ sign fares better in terms of open rates:
Subject lines containing the $ sign had a 29% open rate on average, compared to the 25% open rate for subject lines containing the % sign.
4. How long should your email subject lines be?
Lastly, we noticed that one of the top brands loves to use long subject lines. This one below has 213 characters:
“COMING SOON: Adidas Originals Equipment Support EQT “White/Turbo-Red” Pack & EQT Support BOOST Ultra “Chinese New Year” / Stussy – Spring/Summer ’17 Collection / New Balance – 247 & Sport Style Clothing Collection”
Naturally, we wondered what effect the length of subject lines has on open rates. We noticed that most email subject lines have between 11 and 50 characters on average.
However, when taken together (for all subject lines between 11-50 characters long) they do not present the best open rates:
Instead, as you can see from the graph above, the subject lines with character counts of 51-90 have a 40.5% average open rate, while the popular 11-50 character subject lines have an average open rate of 33.8%.
However, we should take into account that the sample size for subject lines with 50+ characters is much smaller than the subject lines with at least 11 characters.
Therefore, subject lines between 21-30 characters have the best open rate, and these subject lines also happen to be most popular.
About the Author : Karolina Petraškienė is a blogger and email enthusiast at Omnisend, the ecommerce marketing automation platform dedicated to helping ecommerce stores build strong, lasting relationships with their customers.