Digital MarketingEmail MarketingSubject Line Testing Scenarios

Subject Line Testing Scenarios

Gauge whether personalization, branding, and subject line length help or hurt e-mail open rates.

E-mail open rates continue to decrease across industries. Yet, as we discussed last time, e-mail delivers the highest ROI (define) of any other marketing vehicle — a whopping $57.25 for every dollar spent on it in 2005, according to the Direct Marketing Association’s “The Power of Direct Marketing.”

To maintain that outstanding ROI momentum, we clearly must write subject lines that get people to open those e-mail messages and unlock the great marketing messages inside.

It’s no secret: I spend more time writing subject lines than writing the e-mail messages themselves — and I’ve shared some tips with you in past columns.

But recently, I read an excerpt from a report by e-mail provider MailerMailer that gave me some new ideas for subject line tests.

Test: Personalization vs. No Personalization

A lot of e-mailers hesitate to use personalization in subject lines for fear of looking spammy. That’s a legitimate concern. But according to MailerMailer’s survey of 270 million e-mail messages from 3,136 in 22 industries from January to June 2007, personalization can dramatically increase open rates.

E-mail in which just the subject lines were personalized got an 18 percent open rate. When the subject line was general but the message inside was personalized, the open rate went down to 16.6 percent.

Interestingly, CTRs (define) on e-mail with personalized subject lines were also better, at 5.0 percent compared to 3.2 percent for general subject lines.

Will this be true for you? That’s something you’ll have to test yourself.

One of my clients, a conference company, experienced a substantial uptick with personalization — and never used it again! Why? Because it doesn’t keep an archive of high-performing e-mail approaches. When its marketing managers moved on, the company lost valuable marketing intelligence.

Another client tried it twice and each time saw a minor improvement. It’s also unlikely to use it again. Personalization uses up vital characters in the subject line and allows less room to get the main message across. And the client just isn’t comfortable with this kind of promotional approach.

However, I’ll keep this tool handy in my personal e-mail copywriting toolkit and use it when I need to pull a rabbit out of my hat to increase open rates.

Test: Shorter Subject Lines vs. Longer Ones

It’s challenging enough to condense a marketing message into 45 characters, the typical length of an e-mail inbox. But MailerMailer metrics show that even this length may be too long. The company found open rates are 5.1 percent higher for subject lines under 35 characters. And that CTRs for e-mail with shorter subject lines are 1.7 points better.

So this is another good test to try. But you may not want to go it alone. It’s always harder to write shorter than it is to write longer — and this is where the art of copywriting comes in. Hire yourself a pro!

Test: Brand Names in Subject Lines

The MailerMailer report recommends using subject lines that include your brand name. I didn’t see any stats in the report backing that up, but I’ve seen statistics elsewhere that support this best practice recommendation. According to JupiterResearch, adding a company name to the subject line can increase open rates by up 32 percent to 60 percent over a subject line without branding.

It’s a worthwhile test, but it’s a tough one because a lot of brand names can take up more than half of your subject line.

For example, I just worked on a conference with a title that was the full 45-character length of an e-mail inbox. Sometimes you can shorten things a little by abbreviating or using acronyms, but only if the shortened brand name is still recognizable by the target audience. Sometimes there are legal reasons you can’t truncate a brand name or company name.

Still, I wonder if the branded subject line is necessary when the sender line uses the brand name. I’ve always considered a branded sender line a bonus, because it establishes instant credibility and lets me off the hook of using the brand name in the subject line. But maybe not. Maybe people need to see the brand name twice. The only way to know for sure is to test it.

Bottom Line: Test and See What Works

With so little wiggle room within a subject line of 35 or 45 characters, you’ll have to test to see what factors are most critical to increasing performance.

Try a new approach on one or two e-mail messages. If it doesn’t work, move on to the next test. If it does, incorporate the winner into the next testing scenario.

Of course, this is just the tip of the iceberg when it comes to testing. You can test:

  • Deadlines to increase urgency
  • Offers
  • Different product features/benefits to see which resonate best with your audience
  • Different messaging types — emotional, intriguing, researched-based, newsy, and so on
  • Even if you find a few winners, you must keep on testing. Because if you’re sending out a weekly or monthly e-mail, you can’t overuse the same subject line approach. Not only will you induce e-mail fatigue in readers, but if your competitors notice you’re using the same approach over and over, they’ll conclude it’s successful and copy it. At that point, you’ll be competing against your own winning approaches!

    Plan for continual testing. And don’t forget to document and archive both your failures and successes. The worst thing is when a company gets marketing amnesia — when everyone forgets what worked or failed in the past — usually because key personnel have moved on. I can only groan when a newbie says, “Hey, why don’t we try x!” as if it were a bright new idea, when we’ve proven conclusively in the past it doesn’t work. Not that you can’t try again in a different way. But don’t spin your wheels by going over and over the same old ground.

    What subject line testing have you done and what’s working (or not!)? Let Karen know for future columns.

    Want more e-mail marketing information? ClickZ E-Mail Reference is an archive of all our e-mail columns, organized by topic.

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