Testing Email Subject Lines

Posted on by Joolz Joseph of The Virtual Marketeer

I recently had an interesting conversation with someone about Subject line testing…”Where do I start?” he asked. Let me help…

You have just a few seconds to generate interest in your email  so a compelling subject line can be key in grabbing readers attention as they scan their inbox.  Testing a couple of ideas to maximise impact is time well spent!


Try doing split tests across a series of emails.
Test a couple of subject lines with 10-20% of audience day the before the final send.
Send the best performing subject line to the bulk of the list


Monitor trends and identify what behaviour recipients demonstrate
Are their variances by sector?
Look beyond opens to clicks and response rates to understand motivations


Branding vs. no branding, placement at the beginning vs. end of subject line
Informative (statements) vs. engaging
Asking questions, clear calls to action
Length: Long (>70 chars) vs. Short (<50)
One vs. multiple value propositions/interest triggers
Personalised vs. non-personalised
Sentence case vs. Title Case vs. Capitalisation
Emotive copy vs. product-price centric
Search engine words vs. website search terms

Getting subject lines ideas
Visit  your own Inbox for ideas. Which subject lines spark your interest and get you opening? Which messages do you delete straight away? Which ones do not delete or file, but never quite get around to reading?

Dare to be different. Often companies stick with  generic subject lines, such as “May Newsletter” to try and appeal to as many people as possible. It helps to remember that generally only 25 to 50 % of recipients are opening your emails to begin with and these are those most likely to do so anyway so something different may reach those apathetic subscribers.

Good luck and let me know how you get on as I am always interested in test results 🙂



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