October 26, 2016

Why I Stopped Following Subject Line Best Practices

Written by

I hate reading about email subject lines.

Like their cousin, the article title, subject lines have been discussed ad nauseam in the marketing blogosphere — to the point where attempting to research the topic drowns you in a torrent of competing best practices.

5.6 million posts represent more information than will ever be necessary about any subject in the history of time.

5.6 million posts represent more information than will ever be necessary about any subject in the history of time.

This post is not the all-powerful-ultimate-marketing-secrets-guide to subject lines. It is a story about how I achieved some dramatic results running a subject line experiment for TechnologyAdvice’s outbound email campaigns.

Given the importance of email for demand generation marketers, these results are something I wanted to share, because I think they reveal an effective technique for creating subject lines.

When I analyzed the results of the experiment, one clear pattern emerged: people respond to headlines that show little to no marketing intent and instead vaguely preview the contents of the email.

Let me explain how I came to this conclusion and what I think it means.

The Catalyst

Like most B2B companies, email is a big part of our strategy at TechnologyAdvice, and it’s part of our marketing mix at all stages of the customer journey. This is means we’re using cold emails to bring people into our marketing funnel.

It’s easy to email people when they already know and like you. If brand loyalty is strong enough, just seeing the sender name can compel someone to open an email. When people don’t know you, it’s substantially more difficult.

I was using lots of the best practices — value-focused words earlier in the subject line, mobile-optimized length, etc. — but the open rates were abysmal for almost every campaign targeting cold prospects.

I knew the content we had was relevant, and our value propositions were compelling, but I still couldn’t convince people to give our emails their attention.


There’s a paradox with marketing email philosophy. Despite all the preaching about personalizing content and building a relationship with people, marketing emails almost never read like something a person would send another person.

Marketing emails almost never read like something a person would send another person.

They sound like something a marketer would send another person. I realized that everyone I was emailing knew I was a marketer, and because they didn’t know my company, they viewed this as a negative thing.

So, I began writing subject lines that didn’t sound at all like marketing. I shifted the focus from the value of the content to simply stating what the content was.

My theory was that people are so inundated with marketing messages that they’ve constructed mental filters to ward off unwanted marketing pitches and conserve their attention. The solution was an antithesis of the marketing best practices I was reading about across the internet.

Here are the tests I ran with this hypothesis in mind:

Test A

Control: Find your perfect software

Treatment: A Short Video

Context: This email was the first in a series targeted at engaging PPC leads who had downloaded one of our buyer’s guides from a paid search ad, but didn’t convert into a lead.



The treatment subject line produced a 115 percent increase in opens by promising less and plainly stating what to expect when you open the email. There’s an element of mystery involved in the treatment headline as well, which is also a significant factor.

Test B

Control: Join 4,000 B2B Companies

Test: Free product page for {{company}}

Context: This email was part of a campaign to convince people to sign their company up for a product page on TechnologyAdvice. The first email uses social proof to persuade people to open the email, while the second just states what the email is about.  



Again, the treatment headline is just a recap of what’s inside the email. It’s not flashy, and you could even say it’s boring. However, the added personalization from the merge field coupled with the allure of something free for your company conveys the offer inside the email without sounding too aggressive.

The percentage increase is more modest here (45%) than in Test A, but it’s still significant.

Test C

Control: Explore the TechnologyAdvice Library

Treatment: An Introduction

Context: This was the first email we sent to the audience segment that knew nothing about TechnologyAdvice. The treatment implies that the sender is interested in making the recipient’s acquaintance, rather than beseeching them to read a piece of content.



These stats further reinforce the idea that people don’t want to be spoken to like “prospects” or members of a “target market.” What appeals to people in this sample of technology buyers is an understatement of what’s inside.

The phrase “an introduction” supplies little detail about the contents of the email (even implies that the copy will be talking mainly about the sender), but it preserves the mystery that compels people to open an email.

What Does This Mean?  

ALSO READ: Remember: B2B Leads Are People, Too

So why do people respond in greater numbers to copy that is plainly descriptive, instead of a value proposition? 

I believe there are two causes.

First, people are inundated with marketing, and most of it is either poorly conceived or irrelevant. People start ignoring it, because they value their sanity. This concept is similar to “banner blindness” theory, which describes why people ignore website elements that resemble ads.

The Hustle has experienced rapid growth using creative headlines

The Hustle has experienced rapid growth using creative headlines.

There’s no good reason to think this wouldn’t happen with email. The fact that there are more than 5 million blog posts about subject line best practices is part of the problem. If email marketers collectively adopt the same techniques, then those techniques will become ineffective — just like the techniques used before them.

The second cause relates to the particular aesthetic of my treatment subject lines. Each one plainly communicates what to expect in the email while leaving room for curiosity. In the most successful test, “A Short Video” outlines the type of content someone will find in the email without describing any details of that content.

There’s no teeth-grinding, neck-bulging declaration of VALUE. It’s a subtle approach.

Loot Crate is one of several companies that more or less sell mystery in a box

Loot Crate is one of several companies that more or less sell mystery in a box.

 This works because people like mystery. They enjoy being surprised. There’s even a chemical in our brain dedicated to anticipating surprises and rewards. It’s why people buy baseball cards and subscribe to Loot Crate and enjoy Christmas.

An email subject line is an excellent medium for piquing someone’s curiosity. It’s all that most people see before they open an email, and if you add just the right amount of mystery, people will be intrigued. This same strategy is used by hugely successful email companies like theSkimm and the Hustle.

* * *

Like I said in the opening, this technique isn’t the end-all-be-all of subject line writing, but it is a tactic that helped me gain more engagement with the always recalcitrant audience of cold prospects.

Given that SDRs and cold outreach are on the climb, it seems pertinent for every demand generation marketer to think of ways to grab a modicum of people’s attention and get them to take the first step in engaging with your brand: opening your email.

Free Download

Marketing Automation Buyer's Guide

Get My Free Guide