Thus, more people might click an email with a nine-word subject line because they had a better sense of the email’s content from the start.
It’s more challenging to be descriptive and actionable in four words than it is in nine words. Therefore, we needed to look at overall engagement, not just open rates. But the click-to-open rates didn’t correlate, meaning high open rates did not correlate to high click-to-open rates. You can see that the highest open rates occurred with four-word length subject lines and the lowest open rates were tied to nine-word length subject lines. Using these two metrics, I then built a mock data set to determine which word count length gave me the highest level of engagement. Then, I pieced out the data by word count for all the campaign metrics listed above with the immediate goal of aggregating average open rates paired with average click-to-open rates. Most of our subject lines fell between four and nine words and just to be safe, I included a 10+ words category. With hundreds of lines of data, I needed to aggregate subject line length by word count. The key here is having a large enough sample size to show some statistical significance.
I bet you can’t guess what happened next! Using Marketo, I ran a report in capturing these attributes and metrics over the past six months, which gave me a large sample size of ~200 email campaigns and over two million emails sent. The question we are really asking is this: based on word/character count, what subject line length gets us the most engagement (clicks)? Click To Tweet To answer this question, we needed the following campaign attributes and metrics: There is a common misconception that the right question to ask would be: which subject line length correlates to the higher open rate? But that doesn’t factor in downstream metrics such as clicks, click-to-open rate, and unsubscribe rates. In this blog, I’ll walk you through how I collected and dissected data to determine the ideal word and character count for writing subject lines that beg to be opened (and lead to a click). Often, the answers to your questions live in the data. As a result, marketers are plagued by a few common questions: How can something possibly be short, fun, eye-catching, enticing, and compelling all at the same time? I know. Subject lines can be one of the most frustrating components of email marketing. Alright fellow marketers, let’s get to the bottom of this.