Our Blog

“Knowledge is knowing a tomato is a fruit. Wisdom is not putting it in a fruit salad.”


  • Categories

Search Blog

Email subject lines in 2019

2018 was a year of big change in the email marketing industry. 

From the push for accessibility to the birth of a new user interface and from AI email marketing’s coming of age to some truly laudable milestones, we’ve watched the internet’s oldest and most lucrative marketing channel reach impressive new pinnacles of success and innovation over the tumultuous past 12 months. Better still, all indications seem to be that the email marketing renaissance will continue in the year to come. 

It’s an exciting time in the email marketing game. 

Here at Phrasee, we’ve experienced the seismic shift our mighty industry is currently undergoing in a much more specific way – through the lens of the humble email subject line. 

Even there, in the single line of attention-grabbing text whose sole purpose in life is to entice recipients to open marketing emails, change is afoot.    

Here’s what’s new in the world of email subject lines in 2019 and why every brand and marketer should be taking note… 


The fight for subscriber attention 

More than 280 billion emails were sent worldwide every day in 2018. By 2020, that number is expected to exceed 300 billion.  

For those keeping count; that’s a lot of emails. 

That means that the world’s inboxes will be even more crowded than ever in 2019 and that user attention will be even harder to capture and hang on to than it was last year.  

Brands will need to experiment with words, sentiments, sentence structures, and emojis on a regular basis to learn what works (and what doesn’t) to stay ahead of the curve and engage their audiences. 

Tracking campaign performance data is now an essential part of any effective email marketing strategy. Brands will need to keep a close watch for dipping email open rates in 2019, as ineffective email subject line language could well result in lost revenue for those who don’t take steps to improve their approach in this area. 


Optimizing email subject lines for voice 

According to data compiled by Nielson, nearly a quarter of all US homes now contain a “smart speaker”. If this technology’s explosion in popularity over the past 18 months is any indication, products like Amazon’s Alexa, Google Home, Facebook’s Portal, and Apple’s HomePod could represent a sea change in the way consumers interact with the internet and the brands which call it home.  

Exactly how this voice-activated interface will affect how consumers use email in the years to come remains murky at this stage, however, Amazon recently announced that it had added a verbal email reading application to its Alexa products. This announcement is indicative of a larger trend toward “voice-ification” that every brand should already be preparing for. 

One thing that is for certain is that the way marketing email subject lines are constructed will need to be optimized for smart-speakers in the very near future as the technology’s adoption spreads. 2019 is the year we’ll all need to figure out exactly what an “optimized for voice” subject line looks like (don’t worry, Phrasee is working on it!) and adjust our email subject line strategies accordingly.  


AI adoption 

If you didn’t hear the phrase “AI is going to change everything” at least once in 2018, you probably haven’t been paying attention.  

2018 was the year that the public finally realized that just because there aren’t robots making us dinner and changing our babies’ diapers yet doesn’t mean that artificial intelligence doesn’t exist. “Narrow”, powerful, task-specific AI moved to the forefront of the marketing industry in 2018 and produced spectacular results. 

Many huge global brands have already taken a leap of faith into the AI marketing age by experimenting with AI-optimized email subject lines to augment their email marketing strategies and boost subscriber engagement.  

With companies like Virgin Holidays publicly attributing upticks in email marketing revenues in the millions of dollars to AI-driven subject lines, it is a safe bet that this game-changing technology will find its way into the email marketing strategies of plenty more brands in the year to come.   


Any way you slice it, 2019 promises to be another interesting year in the ever-changing realm of email subject lines. 

That is, as long as email subject lines are the kind of thing you find “interesting”.  

Luckily for us (and our customers), we do!  

If you want to see what Phrasee’s awesome AI email subject line optimization can do for you and your brand, book a demo today!

The email marketing strategy playbook for 2021

The email marketing strategy playbook for 2021

With 2021 just around the corner, is your email marketing strategy ready? From personalization to segmentation and optimization to tracking, we share best practices for building an effective email marketing strategy.

Discover how applying actual AI to language can deliver big results!