A recent study by MailChimp, is prefaced by saying that people quickly scan the subject lines in their inbox before deciding which messages are worth their time and attention. With so much pressure on
the subject line to entice the potential reader, the study was designed to determine how much of a difference a single word can make in a campaign’s open rate.
Approximately 24 billion
delivered emails with subject lines composed of approximately 22,000 distinct words were studied, looking at subject lines both in general and within specific industries. The numbers presented are
standard deviations from the mean open rate for a user/list. Words with positive impacts resulted in increased open rates, and words with negative impacts hurt those same rates. It’s
important to know, says the report, that a standard deviation is a standardized measurement of how much something deviates from the average value.
The analysis found that personalization does
indeed increase open rates. One of the most interesting findings is that, though the use of both first and last names in a subject is less common, it has the largest positive impact on open rates.
Name Personalization (Impact on Open Rate; in Standard Deviations)
- First and last name 0.33
- Last name
only 0.17
- First name only 0.09
First name
personalization is used much more frequently than last or full names. The study focused on industries where the impact was significant, and found that there are several industries where use of the
first name has a large positive impact. The most surprising finding, however, is that first name personalization has a negative impact on open rates for the legal industry.
First Name Personalization in Selected Industries Impact on Open Rate in Standard
Deviations |
Industry | Standard Deviation |
Government | 0.92 |
Creative services/agency | 0.45 |
Politics | 0.30 |
Computers and electronics | 0.28 |
Hobbies | 0.26 |
Software and web apps | 0.20 |
Non-profit | 0.18 |
Arts and artists | 0.17 |
Entertainment and events | 0.16 |
Retail | 0.14 |
Education and training | 0.13 |
Marketing and
advertising | 0.13 |
Business and finance | 0.11 |
Legal | - 0.11 |
Source: MailChimp, November 2013 |
Including “free” in the subject line entices potential readers to open the
message, but not always, says the report. Using “free” in a subject was found to be positive and statistically significant for certain industries, it was smaller when looking at all
industries on a higher level. Interestingly, use of the word “freebie” was found to result in a much larger increase in open rates.
Free vs. Freebie (Impact on Open Rate in
Standard Deviations)
The top level results suggest that using “free” doesn’t have a large impact, but at the industry level people in the medical, retail, and travel industries
should avoid using the word “free,” and restaurant and entertainment industries can certainly benefit from it.
Use of Free in Select Industries (Impact on Open Rate in Standard Deviations) |
Industry | Deviation |
Recruitment and Staffing | 0.45 |
Restaurant % Venue | 0.11 |
Beauty and Personal Care | 0.11 |
Arts and Artists | 0.08 |
Music and Musicians | 0.07 |
Entertainment and Events | 0.07 |
Ecommerce | 0.06 |
Education and Training | 0.05 |
Media and Publishing | 0.04 |
Retail | -0.04 |
Business and Finance | -0.09 |
Medical, Dental and Healthcare | -0.15 |
Real Estate | -0.15 |
Travel and Transportation | -0.25 |
Source: MailChimp, November 2013 |
Attention-grabbing words like “urgent” and “important” resulted in open rates
that were much higher than normal.
Words That Imply Time Sensitivity
Impact on Open Rate (Standard Deviation)
- Urgent 0.79
- Breaking 0.68
- Important 0.55
- Alert 0.31
Source:
MailChimp, November 2013
Recipients are much more intrigued by announcements and event invitations than cancellations and reminders. It would appear that repeated reminders and
cancellations don’t pique their interest quite as much.
Announcements, Invitations and Cancellations
- Announcement 0.46
- Invitation 0.34
- Invited 0.34
- Announcing 0.32
- Invite 0.28
- Invites 0.28
- Announced 0.26
- Announces 0.21
- Announce 0.21
- Reminders 0.12
- Announcements 0.10
- Reminder -0.29
- Cancelled -0.40
Source: MailChimp, November 2013
It might make sense that people don’t open
emails about cancelled events. Sometimes the title says it all. What the study found is that using “cancelled” in subject lines is negative whenever the impact is significant, except for
in the restaurant industry, where recipients seem more interested in reading on.
Use of Cancelled in Selected Industries |
Impact on Open Rate (Standard Deviations) |
Restaurant and Venue | 0.41 |
Sports | -0.24 |
Agriculture and Food Service | -0.32 |
Government | -0.33 |
Religion | 0.38 |
Non-Profit | 0.39 |
Media and Publishing | -0.40 |
Education and Training | -0.47 |
Beauty and Personal
Care | -0.51 |
Health and Fitness | 0.57 |
Hobbies | 0.92 |
Arts and Artists | -0.94 |
Business and finance | -0.99 |
Social Networks and Online Communities | -1.16 |
Professional Services | -1.17 |
Source: MailChimp, November 2013 |
Words related to charitable actions and donations had a negative impact on
open rates. Although all these words negatively impact open rates, “donation” had the most negative impact. “Helping” had the best impact, though it can obviously be used in
more contexts.
Words Associated with Charity |
| Impact on Open Rate (Standard Deviations) |
Helping | 10.12 |
Fundraising | 0.13 |
Raffle | -0.14 |
Fundraiser | -0.17 |
Charity | -0.18 |
Donate | -0.56 |
Source: MailChimp, November 2013 |
Frequently used word pairs often have significant impacts on open rates. Sometimes two words can provide context that a single word can’t convey. We thought it would be interesting
to see how some of these word pairs perform. People love to be thanked. And, campaigns about current events, like natural disasters and political issues, have higher open rates than normal. And
recipients don’t like to be asked to sign up for anything, and they really don’t like being told they’re missing their last chance to get something they’ve already been
emailed about, notes the report.
Frequently Used Word Pairs |
| Impact on Open Rate (Standard Deviations) |
Thank you | 0.57 |
Supreme Court | 0.51 |
Appeals Court | 0.32 |
Hurricane
Sandy | 0.19 |
Sneak peek | 0.08 |
Sign up | -0.18 |
Breast cancer | -0.27 |
Last chance | -0.45 |
Source: MailChimp, November 2013 |
Concluding, the report says that any of these results can be applied to
campaigns in a straightforward way. For example, these things are likely to increase open rates:
- Personalizing subjects
- Marking appropriate emails as urgent
- Thanking
your recipients
And, choosing words wisely when soliciting donations or reminding your recipients of upcoming events can minimize the number of unopened emails. The more interesting
takeaway, says the report, is that a single word’s presence can dramatically alter the likelihood that readers will open emails. The content of the message is really what determines which words
you use, but with so few words in a subject line, each one matters quite a lot.
For more information from
MailChimp, please visit here.