LONDON: Nearly three-quarters (71%) of marketing emails were opened on mobile devices in the UK in the first quarter of 2015, but purchase conversion rates were higher on desktops, a new study has revealed.

According to the UK Consumer Device Preference Report by US email marketing firm Movable Ink and released to Marketing Week, 42% of emails were opened on smartphones during Q1 2015 while 29% each were opened on tablets and desktops.

However, out of the more than 120m B2C emails tracked in the study, desktop accounted for 39% of email conversions compared with 37% on tablets and 25% on smartphones.

The findings prompted Movable Ink CEO, Vivek Sharma, to suggest many brands are failing to optimise their emails for mobile devices and that they need to improve the "post-click experience" for consumers.

"Given that over 70% of engagement is happening on mobile devices, it is something all brands should consider," he said.

"Marketers should not only think about the form factor and [creating] simpler messages on a mobile phone – they need to think about the post-click experience and how to make it as frictionless as possible," he added.

In effect, he advised brand marketers to make better use of multiple sets of data so they can personalise and improve email marketing campaigns for mobile users.

For example, the study found that more than half of all emails were opened on smartphones between midnight and 7.30am, which meant marketing emails sent at night or the early hours would be more effective if designed for small screens.

Similarly, tablet users were found to be much more likely to spend time reading emails, suggesting they could be more receptive to long-form sales copy.

More than two-thirds (69%) of Kindle Fire users said they read emails for 15 seconds or more compared with just 39% of iPhone users, 41% of whom said they only glance at an email for three seconds or less.

"You can no longer have a static, one-size-fits-all experience for all of your consumers," Sharma said. "If 10m emails go out, there should be 10m unique experiences created based on that individualised context."

Data sourced from Marketing Week, Movable Ink; additional content by Warc staff