Real Results to Common Email Tests

Email Marketing


We always talk about what to test in your email marketing campaigns, but what are the outcomes? At Marketo, we’ve run 100s of email tests to discover what resonates well with our target audience. We have tested subject lines, messaging, personalization, from lines, and the list goes on and on. So, what have we found to be the most effective?

Take a look at some examples of the tests we have run, along with our findings–though keep in mind that this is what works for us, and your results may vary. But don’t be afraid to try some of these tests to see what works for your audience! And if you want to learn more about email testing, download our new cheat sheet What to Test in Your Emails.

From Label (Person vs. Alias)

To conduct this test, your email marketing solution must have the capability to insert personalized token information and/or merge field capability. Version A was sent from a human being (the lead’s owner); version B was sent from a general marketing alias; the subject lines were identical.

Here are examples of the two versions:

  • Version A From Name: Ryan Hammer, Marketo
  • Version B From Name: Marketo Premium Content

The winner
Version A, which increased opens by 28% and increased CTR by 8%. Our hypothesis is that an email from a real person appears more engaging.

Fake Forward

In our Fake Forward test, we tested an email that appeared as if a sales rep forwarded it to the subscriber to an email that was directly from that sales rep.

The winner
The test showed Fake Forward had significantly higher Open Rate (2% higher) and Click-to-Open Rate (2% higher).


Think salutations don’t matter? Think again. Our test compared an email that included a salutation (e.g., Dear [First Name]) with one that didn’t. The subject lines were the same.

The winner
The email with a salutation resulted in an almost 2.5% increase in Click-to-Opens, which translates to 49 more clicks. It was significant with a 95% confidence level, while open rates did not significantly differ.

Email Body Length

Does shorter, more concise email content lead to more click-throughs than highly descriptive, longer email content?

The winner
We conducted two tests, both of which showed significant results in favor of shorter, more concise content. Our first test resulted in a 7% increase in Click-to-Opens, equating to 38 more clicks. The second test generated a 2% increase in Click-to-Opens, which translates to 66 more clicks. We believe difference exists because not only are short emails less likely to overwhelm readers, but also they’re not cluttered by text, so the CTA appears prominently.

Bracketed Offer in Subject Line

This test applies to emails that offer a content asset. We tested two versions of subject lines by naming the asset (New eBook) in one and simply placing the word “Download” in brackets in the other:

  • Version A: [Download] Make Your Facebook Posts More Shareable
  • Version B: [New eBook] Make Your Facebook Posts More Shareable

The winner
Interestingly, the Open Rates did not differ. However, the click through was higher for the email that contained the word Download. That, we believe, is because the word Download doesn’t just alert readers to an asset, but also instructs readers how to obtain that asset. In terms of confidence, the results were significant to 80%.

Want to learn more email marketing? Download our brand new 150 page guide The Definitive Guide to Engaging Email Marketing.