Plain Text vs. HTML Emails: Which Is Better?

I can’t believe I’m linking to HubSpot, but let truth come from whence it may.

I’ve long been a fan of plain text emails (really plain text anything). And now I have some serious data to back up my gut feeling.

Aside from proper list segmentation, nothing boosts opens and clicks as well as an old school, plain-text email.

What’s really interesting about this data is that people say they prefer HTML emails and visuals, but the data shows the opposite of what people say:

In a 2014 survey, we asked over a thousand professionals whether they preferred HTML-based or text-based emails, and whether they preferred emails that consisted of mostly text or mostly images. Nearly 2/3 of the respondents said they preferred HTML and image-based emails...[However] In every single A/B test...The emails with fewer HTML elements won with statistical significance.

The authors of the article I think get to the root of what I’ve always felt about email: it’s a 1-to-1 interaction:

For example, shouldn't an email with an image of the ebook being promoted do better than an email with no visualization of the offer? Wouldn't just a plain email be boring, and not help explain the offer? Aren't humans wired to be attracted to beautiful design?

Unfortunately, this principle doesn't apply to email.

And the reason is simple: Email, unlike other marketing channels, is perceived as a 1-to-1 interaction.

Think about how you email colleagues and friends: Do you usually add images or use well-designed templates? Probably not, and neither does your audience. They're used to using email to communicate in a personal way, so emails from companies that look more personal will resonate more.

Again the data backing these claims up is quite significant:

For the click rate, we dove into data from over half a billion marketing emails sent from HubSpot customers. These customers vary in type of business, and have different segments, list sizes, and list compositions.

What we found was that even a single image reduced the click rate

That plain text performs better than HTML emails is no small claim, especially from a marketing company like HubSpot. The cynical part of me doubts that much will come of it, though. As the author of the article states:

Ultimately, in email, less is more.

This can be a tough pill for marketers to swallow (myself included)...But data repeatedly shows plain-text email wins, so it's up to us to decide whether or not we want to make the switch.

At least now I’ve got some good data to backup my gut.