Keeping email recipients engaged with images

I’ve been experimenting recently with putting images in emails, using standard A/B testing (half the circulation got images, the other half didn’t). I’m fairly certain that the increase in clickthroughs for the image emails is statistically significant, so I’ve been doing some homework on best practice for including the images. The general rules seem to be – as they always have been – fairly straightforward:

  • Work hard on getting the best image quality/image size tradeoff (beautifully sharp PNG files aren’t always as big as you might think);
  • Make the images clickable, but not at the expense of a text (or better, button) link;
  • Ensure the same image appears at the first glance on the landing page (for reassurance); and
  • Include ALT text.

Images won’t get you a higher open-rate – nobody knows the content of the email before they open it – but they can pique the recipient’s interest or keep them engaged as they scroll down a long message.