When I was in high school, our teacher gave us an assignment to write a speech on a single 3×5 note card.  Even writing real small, it forced us to focus on the most important content and think about each and every word.  A recent study by Epsilon on subject lines reminds us to do the same with email copy.

Epsilon recently released the results of a study on subject line length which supports the generally held notion that shorter subject lines perform better (although the correlation may not be as strong as believed).  Shorter subject lines often do better for technical reasons as many email clients show fewer than 50 characters.  According to Epsilon, 57% of U.S. email recipients see only the first 38 to 47 characters of a subject line when making the decision to open an email.

However, as the Epsilon report notes, the focus on the subject line length itself can camouflage two critical factors for success:  word choice and word placement.  Given the variety of email clients and continued growth of people reading email on mobile devices, the number of characters of a subject line that is visible could be 25 characters or 65.  That is why it is key to place the most important part of your message at the beginning of the subject line and carefully consider each and every word.

Now that doesn’t mean you should never use longer subject lines.  There are many situations in which a longer subject line is warranted and will perform better (the report provides an example).  As such, it is important to continually test elements like placement  (e.g. Ends Today: 10% Off vs. 10% Off Through Friday), word selection (e.g. Ends Today vs. Last Chance), inclusion of your brand, and mentioning specific savings instead of a more general reference (10% off vs. Sale).