Sometimes it feels as though omnichannel marketing is more of a science than an art. With each split test, heat map, and cookie, marketing has become riddled with technical jargon and best practices. However, when every company imaginable is pushing out those “Top Trends for <Next Year>” reports in the winter, there’s a much foggier choice to be made: Should you follow the trends or purposefully not?

To date, there hasn’t really been a right answer to this question. However, if your goal is to make an email that is interesting to a reader, we may have just found a telling correlation.

Subject lines— the suit and tie of your email’s first date with a potential customer — can be notoriously lame. But does it really matter? We think so.

After tracking over 800 welcome emails throughout 2014 and flagging interesting emails as we went, we’ve found a positive link between the uniqueness of subject lines and reader interest. (And if someone can truly dub an email interesting after flipping through several thousands of them, you know it must be good.)

First, let’s look at the top words used in welcome series’ subject lines, as seen in the chart. Not the most inspiring list, yet together those ten words made up almost half of all words used in these 800+ surveyed emails.

When ten words make up almost half of the vocabulary, it’s not shocking that only 25.84% of all words surveyed were unique. Interested in how this would stack up, we investigated our well-stocked pile of over 125 interesting emails spanning from 2013 to 2015.

Not surprisingly, we see a huge jump between welcome emails and the average for emails dubbed interesting by Listrak employees. Coincidence? We think not. It seems, for subject lines anyway, sticking with the trends and typical phrasing could lower your chances of interesting a reader.

Moral of the story? While a subject line alone is likely not the sole justification for an email’s level of intrigue, there seems to be correlation enough to take a second look before sending another soulless “Thanks for signing up!” or “Welcome to your new account!” Make the most of your subject lines, and see how your engagement levels change of time.

Have you experimented with your subject lines recently? What did you find?

‍