Landing page research firm Marketing Sherpa is known for their terrific stats on what works best in sales copy, email marketing and more. They offer a pretty pricey subscription to access everything on the website, but non-subscribers can get free access to articles for a limited time.
Since a recent survey of non-subscribers had shown 68% didn’t know how long the free access lasted, they decided to test if adding the article’s expiration date in the email subject line would improve response…
Seems like a no-brainer, right?
Because in general, adding some form of believable urgency to an offer boosts response–often quite a lot. (In this case, the subject line is offering great info inside.)
But not this time. After 10 weeks, they reviewed the data and found that adding the expiration date to the email subject line had the OPPOSITE effect…
Slightly decreasing open rates and clicks versus the same exact email subject line without the expiration date.
As I’ve said before, people aren’t always rational and what works doesn’t always make sense. It could be the recipients thought they had less time than they really had, so seeing the real date made them more likely to procrastinate. Who knows.
Of course, just because it didn’t work for Marketing Sherpa doesn’t mean adding a deadline to your subject lines wouldn’t work…
Bottom line–with email subject lines (or anything!), it’s good to start with rules of thumb, but always test, test, test because nothing works 100% of the time.
