Crafting the Best Email Subject Line is an Art

Crafting the Best Email Subject Line is an Art


The most important part of an email is a subject line and it is also the most frustrating component of email marketing. It’s really difficult to understand that how can something possibly be short, eye-catching, attractive, fun, and compelling all at the same time? Mostly marketers faced difficulty when writing a subject line and they are plagued by these common question:

Are lengthy lines not good?

What is the best word count?

Does the length of subject line really important?

Well the answer to your questions are describe in the data. In this blog I will explain that how I gathered and dissected data to determine the perfect word count and character count for writing a catchy subject line that immediately grabs the attention.

1. Data Collection

There is a typical misguided judgment that the correct question to inquire would be: which subject line length relates to the higher open rate? In any case, that doesn’t factor in downstream metrics, for example, clicks, click-to-open rate, and unsubscribe rates. The query we are truly inquire about is this: based on word/character count, what subject line length gets us the most traffic (clicks)? To respond this query, we required the following metrics and campaign attributes:

  • Subject line
  • Sent
  • Delivered
  • Unique opens
  • Open rate %
  • Clicks
  • Click-to-open rate %
  • Unsubscribe rate %

I ran a report in catching these traits and measurements for past six months, which gave me an enormous sample size of 200 email campaigns and more than two million messages sent. The key here is having a sufficiently huge sample size to demonstrate some factual significance.

2. Analyzing the Data

With several lines of information, I expected to total subject line length by word tally. The greater part of our titles fell somewhere in the range of four and nine words and as a sanity check, I incorporated a 10+ word’s category. At that point, I pieced out the information by word count for all the mentioned above campaign metrics with the prompt objective of gathering average open rates paired with average click to-open rates. Utilizing these two metrics, I at that point assembled a mock informational collection to figure out which word count length gave me the most engaging traffic signs.

Here’s the data:

Analyzing the Data

As you see that the most noteworthy open rates happened with four-word length title lines and the least open rates were attached to nine-word length title lines. But we see that the click to open rate didn’t connect, so it shows, high open rates did not link to high click-to-open rates.

Consequently, we expected to take a gander at overall involvement, not simply open rates. It bodes well as well. It’s even more challenging to be engaging and noteworthy in four words than it is in nine words. In this way, more individuals may click an email with a nine-word subject line since they had a superior feeling of the email’s content from the beginning.

3. Take the data and model it out

Now it’s time to take the averages of word count and factor them into a model with constant variables so that we can get the result about which subject line length is perfect in generating the best overall engagement rates. For this purpose, I use the following metrices: open rate, sent, opens, click and click-to-open rate.

It is the model, using 100,000 emails sent as our constant variable:

3. Take the data and model it out

Well the victory goes to seven words for overall engagement. But the shocking part is that if you create an eight-word subject line, the performance is nearly half as subject lines with one less word.

So hopefully with this process now you have get the idea about how to evaluate your perfect subject lines for click-to-open rates, open rate and overall email engagement. Also, if you’re doubting about what the ideal character count would be, so our seven-word subject lines have an average of 41-word count characters. But the fact is that, it is easy to count words than its characters.