We work in an increasingly mobile-oriented world. The Pew Research Center found that the use of phones to read email doubled between 2009 and 2013, and the November 2014 Ericsson Mobility Report estimated that smartphone subscriptions and traffic per phone would have respective annual growth rates of 15% and 25% until 2020. These trends raise many questions, especially for email marketers. Here are two key ones: What will mobile’s impact be on email engagement? Can email campaign design counteract changing engagement rates?

Methodology

We analyzed a random subset of email addresses that Mailchimp sends to and determined their corresponding devices using user agent strings. For each address, we considered the device that registered the most clicks as that user’s preferred device. To focus on actively engaged recipients, we only included addresses that had clicked on an email campaign since the beginning of 2013.

We aggregated sends and clicks from Mailchimp users within a six-month period to explore how preferred device type impacts engagement. We also examined whether using Inbox Preview and responsive templates helped engage mobile subscribers, and how link placement within a campaign affects engagement.

Readers Click Less on Mobile

PCs, tablets, and mobile devices accounted for 64%, 9%, and 27% of email addresses, and 72%, 9%, and 18% of clicks, respectively. Clearly, PC users are more likely to click.

Unique click rates measure the percentage of sends that received at least one click, while total click rates allow for multiple clicks per campaign. PC and tablet users had unique click rates of 3.8%, a 40% increase over the mobile rate of 2.7%.

PC users also tend to click on more links per email. Their total click rate is 6.7%, compared to 5.6% for tablet users and just 3.9% for mobile users.

Deeper Links Get Fewer Clicks

Lower mobile engagement affects all parts of a campaign. We examined click rates by link depth—how far into the email the link appears. We only considered links with a depth of 10 or less.

Although total campaign click rates range from 4% to 6%, clicks are not evenly distributed. Individual link click rates typically range from 0.25% to 1.5%. Deeper links consistently get fewer clicks. The fifth link in a campaign, for example, gets about half as many clicks as the first.

Responsive Design Can Improve Engagement

There’s good news for email designers. Responsive templates—those that adapt to different devices and screen sizes—consistently outperform non-responsive templates across all devices. Mobile users especially benefit: unique click rates increase from 2.7% to 3.1%, a 15% improvement.

The benefit of responsive templates is most pronounced in the first 3–5 links of a campaign.

Inbox Preview Drives Higher Click Rates

Mailchimp users can also use Inbox Preview, a tool that shows how emails will appear on various devices before sending. This feature boosts clicks by 13%–24%, with the strongest gains seen among mobile and tablet users.

Inbox Preview also leads to more evenly distributed clicks across the campaign. While clicks on top links drop slightly, click rates on deeper links increase significantly. In fact, the tenth link in tested campaigns received double the clicks compared to those in non-tested campaigns and performed on par with the fifth link in those non-tested emails.

Design Emails That Fit Mobile Attention Spans

Designing campaigns with mobile users in mind ensures your message reaches and resonates with them. Whether or not new devices like smartwatches and AR glasses disrupt current patterns, creating mobile-friendly campaigns now will help you stay ahead.