Ok, so if you read Part 1 of our Email Optimization e-book about Email Deliverability: How to stay out of Spam ; you’ve made it to the inbox…but now what? Well, now you need them to actually open your email…and you have about 2 seconds to get their attention.

Here are a few tactics to use when writing killer subject lines:

The Curious George

These subject lines are often unconventional or mysterious, but they serve to pique the interest of customers just enough for them to want to solve the puzzle (and voilà! Higher open rates). Careful though, you can’t use this type of subject line too often or you may be typecast as a “click bait” sender; which would have the opposite effect on open rates. Emojis can also be used to enhance your message effectiveness.


These subject lines are usually “urgent” in nature and play on the user’s Fear Of Missing Out (FOMO) by mentioning a deadline, limited quantities or scarce availability. They have a “must-act-now” vibe so that users rush to open them. These subject lines also convey the immediate value to the users or the benefit/reward/gain of the content inside… think: what’s in it for me? Unlike the Curious George, this subject line speaks to the direct benefit of the email as opposed to using ambiguity. Similarly however, this tactic should also not be abused, so that you don’t lose credibility among your users.


The In Case You Missed It (ICYMI) subject lines let your customers know about helpful information or trending news they may not have seen and positions your company as a subject matter expert. People like to be “in the know” and value being the first to hear about new developments in their fields of interest. Open Rates are usually higher for these because of the “breaking news” approach that can give customers a perceived competitive edge.

The Personal Touch

These subject lines are tailored specifically to the end user, resulting in higher than usual open rates, since they are very relevant and often well timed. For these, try to pull any related data you may have on a customer and use it against them (well, in a good way). Be helpful, thoughtful or pertinent… and try to go beyond just using their first name in the subject line.

So, in summary, try to use a variety of the above techniques so that you can eventually see what technique works best with your audience. Measure Open Rates over the course of a few weeks and AB test as much as possible when unsure. When looking at Open Rates, don’t forget to take into account seasonality of messages (is there a slump in the summer?), peak periods during the year (Black Friday, Cyber Monday and Holiday for example) or other initiatives in the media mix that may have affected them. 

Read Part 3 of this whitepaper, Content is King and Context is Queen. Leave us your comments below and subscribe to our newsletter right at the bottom of this page.