Subject Lines Live – Best of October 2021

The clocks might have changed, but our inboxes haven’t! Here are the most attention-grabbing email subject lines from October 2021.

The daily top 5 can be found here. 

The Top 5 

Subject Line  CTR (%) 
MDR Software Update  88.84 
PackFlow EPR Report – Here is your download  87.32 
Download the Key Risk Indicators White Paper  83.19 
Risk Culture – Operational Risk Sound Practice Guidance White Paper Download  72.92 
Your Download – [sender] #[CONTENT/MERGEFIELD1]# Brochure  72.11 


MDR Software Update 

Last month’s winner retains its crown, with a 0.2% increase in its CTR! 

By getting straight to the point, rather than carrying unnecessary ”fluff”, this subject line flags that it is important to the recipient. Adding “CRITICAL – READ NOW” or something similar would actually devalue the message, along the lines of the “don’t tell, show” principle. 


PackFlow EPR Report – Here is your download 

Putting the name of the resource in question at the beginning of the subject line is a smart choice, as the continued growth of mobile means that more and more recipients will be opening their emails on a smaller screen. 


Download the Key Risk Indicators White Paper 

A good call to action should tell your lead exactly what you want them to do, and this subject line certainly does that. 

If you know your audience well, you should have a good sense of what content they will be interested in. A CTR above 80% is a good indicator that the marketing team behind this email have their targeting pretty spot on. 


Risk Culture – Operational Risk Sound Practice Guidance White Paper Download 

The longest of the 3 “here’s your download” emails, this is surprisingly not the weakest performer. As well as length, repeating the word risk makes it sound clunky. 

Clearly, the lesson is to be led by results, not by one person’s impression! 


Your Download – [sender] #[CONTENT/MERGEFIELD1]# Brochure 

Out of 3 “resource delivery” emails, this is the only one to include the sender company name. 

According to Databox, most marketers publish a new piece of content more than once a week. That’s a lot of stats, facts and thought leadership to keep on top of!

This means that a little reminder of who provided a particular resource can be helpful. When your lead gets another email from you, they can easily find the initial resource that you sent and use it to decide if they want to engage with you. 


In Other News 


For the first time this month, we decided to look at the length in words as well as in characters. 

The vast majority of subject lines, 77%, were between 1 and 10 words long. This is unsurprising, as the longer your subject line, the more will be lost to the limits of screen size in your recipient’s inbox. The shortest of all this month was a masterclass in getting straight to the point with a tempting offer: 

“Free Drupal 9” 


In contrast, the longest went hell for leather, cramming almost as much into the subject line as the average email contains:  

“Slugcatcher on the pain of downgrades; Woodside to build A$1B hydrogen production hub in Kwinana; Origin to sell 10% stake of APLNG for A$2.1B; Comet Ridge confirms strong shows at Mahalo; Metgasco and Vintage commence Cooper flowtest and more” (39 words) 



Subject lines using personalisation were the most common that they’ve been since we started counting, making up 18.67% of the month’s top contenders. This appears to be a “low-risk, low-reward” strategy, as while the best performer with personalisation was nowhere near as effective as the best -non-personalised subject line, there was a much narrower gap between best and worst for the personalised set (40 percentage points difference vs. 87). However, non-personalised subject lines performed 2% better on average. 



Who? Only 3% of October subject lines chose to spice things up with an emoji. It seems like the majority have made the right decision, as emoji-less subject lines performed over 50% better on average (17.37% average CTR vs. 11.51%) 


Sender’s Company Name 

The vast majority of October’s subject lines (84.67%) chose not to include their company name. However, those that did performed better on average (19.42% average CTR vs. 16.76%), and the highest scorer from the group slightly out-performed the highest scoring of the non-Company Name users ( 88.84% CTR vs. 88.46%) 



Sales/Marketing sends occupy over half of the table (52.67%). Both Event sends and Newsletters were also down on the previous month (by 6 and 4 percentage points respectively). Functional emails (Confirmation Opt-Ins, Resource Downloads etc.) chalked up the biggest proportion since May, with 19.33% of the total pot.  


What will you do with these insights? 

Are you the “high risk, high reward” type? If so then avoiding personalisation seems to be your best way forward. If you’d rather play it safe, then brevity is your friend. You’ll be in good company.  

Happy testing! 


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