If you've read Email Persuasion you'll know that I recommend writing your emails in an informal style: as if you were chatting to a good business friend over coffee.

Every now and then I get asked “why?” Especially given that the dominant style of writing business emails is much more “professional” (ie stiff and formal).

My recommendation comes mostly from personal experience. I started getting better results (more interactions and more sales) the more I wrote informally. And partly because writing informally is a generally accepted best practice for sales letters.

But honestly, I wasn't quite sure that was enough. I wanted some real, solid evidence that writing informally worked.

Strangely enough, there seems to have been very little testing done on informal vs formal writing in the marketing world. It's just kind of accepted wisdom that informal works best.

But there has been quite a bit of testing done in other fields, notably in online learning.

In a meta analysis published in Teacher Magazine in 2015, Professors Paul Ginns, Herbert Marsh and Andrew Martin analysed multiple studies looking at the impact of formal vs informal communication on the effectiveness of online learning.

The studies they looked at covered four primary aspects of informal vs formal communication:

• The use of first/second person vs third person language – ie talking about I/we and you.
• Adding sentences which directly address the reader – for example “Let me tell you what happens when lightning forms…”.
• The use of polite requests rather than direct commands (e.g. “Why don't we save the factory now?” vs “Save the factory now”) – just like we would do if we were speaking to a friend face to face.
• Making the author's view and personality more visible.

The results?

Students who studied from more conversational instructions rated them as more friendly and less difficult. And when there was a more personal and conversational style in the writing, students remembered the material better and were able to transfer that knowledge to new problems.

In other words, when it comes to online learning: informal wins.

Why does an informal, conversational style work?

Some of the earliest researchers in the field, Richard Mayer and Ruth Clark, hypothesised that it's because from an early age we're socialised to pay attention to conversations.

Conversations are where the most important information in our life comes from. And woe betide us if we don't pay attention when our parents are talking to us (frankly, I think this socialisation continues well into adulthood – I know I'm in big trouble if I don't pay attention when Kathy tells me something ;) )

So when we read material written in conversational style that mentions I and you, that talks to us directly, and that makes the human being doing the communication very real and personal; we pay attention just the same as if we were having a face to face conversation.

In online learning, attention results in understanding.

In email marketing, attention results in taking action.

That's why you should write informally and conversationally in your emails.