Trends Q: Are mobile devices rewarding shorter resort subject lines with higher open rates?

Over two years ago we compared a subject line’s length to its open rate and found a very clear trend: shorter gets more opens. But with more and more emails being opened on mobile devices where apps often only show the first 30-40 characters of a subject line, is this effect being exaggerated? Here’s what we found.

The Goods
We did the last such analysis at the end of May 2012, but with new clients and more historical email data since then, we started over with new rules to better compare subject lines from campaigns sent before the last publish date (May 29, 2012) to those sent after. The average open rate is on the Y axis with subject line length (in characters) on the X axis.

After seeing much higher open rates for shorter subject lines in the post-2012 group, the two lines actually interesected for our sample when subject lines hit about about 80-85 characters in length.

What This Means
The fact that open rates for shorter subject lines has grown while open rates for longer subject lines has remained nearly the same suggests that our suspicion may be right. In other words, email subjects that better fit the limitations of mobile apps seem to be rewarded with opens.

Of all the things your resort may split test, this may be a good one to experiment with. Start with your typical subject line and then, in the “B” version, try to create a variation that’s half as long as see how it compares. A few such campaigns could better identify if this holds true for your guests.

Onward and Upward
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