Personalization makes for effective email marketing campaigns. But how do you determine which messaging will work best for various audience segments? Email testing can help you optimize various components of your marketing program.

1. Email testing basics to increase your
email conversion rate
Yazmin Harris
Analyst
1.877.937.6245 | sales@yesmail.com | www.yesmail.com
Email testing is the technique of using a small segment of a subscriber base to test different components
of an email campaign and assess how they can be optimized. Through testing, marketers can find out
what subject lines, offer types, pre-header text, imagery, time of deployment, etc. yield the best results
prior to a campaign’s official deployment to the complete database.
“What makes email marketing particularly effective
is the ability to create personalized messages that
cater to various customer preferences. But how
do we know which messaging strategy would
resonate most with what audience? With email
testing, marketers can easily determine what works
best for each audience segment.”
Email testing enables you to more effectively reach your subscribers by optimizing your email program
and delivering a better customer experience. This, in turn, leads to higher open and click rates, continued
subscriber engagement, and ultimately better ROI from your email marketing efforts.
Why is testing critical to an email program?#2
What is it?#1

2. 1.877.937.6245 | sales@yesmail.com | www.yesmail.com
Before starting to test, marketers should be familiar with proper statistical practices to ensure valid results.
Below are 3 things to keep in mind:
1. Appropriate sample size: Verify that your subscriber base (and your resulting sample size) is
large enough based on estimated expected response rates and is also representative of your
subscriber base.
2. Pulling your sample: Use the simple Random Sampling (SRS) method. This gives each subscriber
an equal chance of being included in your test, therefore avoiding any bias in the test results.
3. Measuring statistical significance: Marketers should strive to be sure that results are reliable and
not due to chance. For instance, a 95% confidence level for a test means that if you ran the same
test again, you are 95% confident that it will yield the same results.
As a start, marketers can implement basic A/B testing to experiment with a number of simple email
components. Here are a few ideas:
• Subject Line: Arguably the most important part of your email, a compelling subject line will convince
your subscribers to open your message. More subscribers opening your emails means a bigger
likelihood for conversion. But how do you know which subject line will capture your audience’s
attention? You can find out by testing different subject line components including personalization,
character length, and offer inclusion.
• Marketing Offer: Some offers may resonate more with your subscribers. You can test different forms
of offers such as percent off, free shipping, or buy one get one free to determine what works best. For
example, sending a message for “Free Shipping” may speak louder to subscribers than “20% off”.
• Time of Day/Day of Week: Are your subscribers early morning risers or night owls? Do they engage
more with your emails on specific days? By testing different times of the day or days of the week for
email deployment, you can determine the best time to maximize engagement.
What components can marketers use if they’re new to testing?
How can marketers get started?
#4
#3

3. 1.877.937.6245 | sales@yesmail.com | www.yesmail.com
Yazmin is currently an Analyst in Social & Disruptive Marketing Strategies,
focusing on bringing innovation to the ESP space. Prior to joining Yesmail, she
worked as a consultant with RR Donnelley in their direct mail division where she
gained valuable experience in critically assessing client objectives in order to
deliver viable marketing solutions. Yazmin has a B.A. in Statistics and a certificate
in Integrated Marketing Communications from Northwestern University.
If you have already mastered the A/B tests, consider adding multivariate testing to your email program.
With multivariate testing, marketers can test multiple email components such as subject line, call-to-
action, or offer type simultaneously, in the same deployment.
Multivariate tests offer notable benefits, including:
• Ability to test multiple email components in a single deployment, which is equivalent to several A/B
tests performed at the same time
• Opportunity to understand how different testing elements interact with each other, potentially
yielding better results
• Capability to isolate testing of program improvements to specific factors such as subject lines and
calls-to-action, so marketers can better understand audience preferences.
With multivariate testing, marketers should keep in mind that the more components you test, the more
email versions you’ll have. For example, testing 2 subject lines, 2 calls-to-action, and 2 offers will equate
to 8 resulting versions of email campaigns to test, compare, and choose from. Therefore, having the right
resources onboard and a large enough sample size will be critical in ensuring statistically significant test
results.
How can marketers optimize more than one email component?#5