Most effective email marketing goes against conventional wisdom

Shorter is not necessarily sweeter – especially when it comes to subject lines in emails. Dela Quist, CEO of London shop Alchemy Worx, says Email marketing analytics have led them to discover a sweet spot for how long subject lines should be.

Suprisingly, open rates climb when the subject lines are in the 50-character range or 80-character range and fall when the length is 60 or 70. It may be counterintuitive, but that’s what the research shows.

Quist relayed the results during the keynote address Saturday at MediaPost's Email Insiders Summit conference. His conference title reflected his findings: "Emailing People Not Lists: Using Customer Based Metrics to Drive Performance Improvement."

Research was culled for more than two years from over 250 million messages. Of those messages there were 660 different subject lines. That’s what’s led him to believe that a 50-character subject line touting a "powerful" offer (30% off Spring Getaway flights to Florida on Delta) is so appealing.

“Find out Secrets to Spice up your Barbecue this weekend and all Summer Long and enter to win a New Weber Grill,” worked well too. The 80-character-plus line describing a newsletter in enticing fashion was powerful, but somehow, subjects in the 60- to-70-character middle, were either too long or not long enough, he said.

Quist has various theories about why the different lengths work. His primary theory however is that  the longer the subject line, the better chance a marketer has of presenting different concepts that may appeal to different consumers. And that – he explains, helps boost open rates. So for instance in the above example, some readers may be interested in ways to improve their grilling. Still others would seek the new grill. Either way, it leads to higher open rates.

Quist's research goes against the conventional wisdom that short subject lines are better. His clients include PayPal and Intercontinental Hotels in the U.S. Both show that "long subject lines work better.”

"Our experience tended towards the belief that long subject lines work better," he said.  Length isn’t all that matters. A more descriptive subject line can also build goodwill with consumers, since it can provide enough info to easily either turn them on or turn them off without having to open the email.