TEST RESULTS: How to choose the best subject line
Nobody can read your email without first opening it, right? Your name and subject line are the only things a recipient sees while making their decision to open or delete your email. ISPs are also using user engagement metrics such as opens, clicks and forwards while making their decision to deliver your email to the recipient's inbox, bulk folder or simply ignore it. Low engagement can lead to poor deliverability.
A couple months ago we wrote an article about choosing email subjects that will convince the recipient to open it and see what's inside. You can see how we selected the subject lines by reading the original article HERE. In summary, we were using the Google Adwords Keyword and Wonder Wheel tools to help us choose words in our subject line based on actual Google search terms verses the subject line proposed by the marketing department. While we did achieve our goal of increasing the open rate, the rest of the test results were a total surprise.
Subject Lines Tested
Marketing Team: Help for your Age Spots, Melasma, Hyperpigmentation
Google Tools: Removing age spots with home remedies
Emails were delivered as an even 50/50 split to 14,000 subscribers and estimated Inbox deliverability for both tests were identical as measured by Return Path's Mailbox Monitor tool. Everything except for the subject lines was identical. Here are the Google subject line numbers.
13.25% HIGHER open rate (hurray!)
57.14% HIGHER unsubscribe rate
30.73% LOWER click through rate
43.75% FEWER orders
56.60% LOWER sales
Higher open rates don't mean better results! We got the boost in open rates we had hoped for proving the effectiveness of the Google tools, but clearly disappointed the readers due to an apparent disconnect between the subject line and the actual email body content. Not only did we send fewer people to the website but we upset many more customers enough to unsubscribe from the mailing list altogether. The lost opportunity cost of never being able to market to these unsubscribed recipients is a cost rarely taken into consideration when adding up the numbers.
Lessons learned: A subject line must support the body content of the email. Even the most seasoned marketers must TEST TEST TEST at every opportunity.