The truth about subject lines

Whenever I do a podcast interview, I can pretty much guarantee that the host will ask me about how to write subject lines.

People get really tangled in knots about this—and I can understand why.

In general copywriting there’s a lot of emphasis on the importance of headlines.

You hear stories about how just changing a headline can result in a 5X increase in sales from the same copy.

And since a subject line is essentially a headline for an email, it seems logical that subject lines are a high stakes game.

That’s not quite true, and here’s why:

One of the major reasons why a good headline can greatly increase response is that it flags down the ideal customer for your offer.

When you’re placing an ad in a printed magazine, or sending out a snail mail letter, or running ads on Facebook, this “flag ‘em down” effect can be huge.

However, once you’ve identified a group of people who are interested in what you sell, the headline choice has a much smaller effect.

Case in point:

Lately I’ve been doing a lot of work with outbound email (aka “cold email”) for B2B service firms.

This process involves carefully building a hyper-targeted list of 5,000 or so contacts and sending them short, personalized emails to gauge their interest in the services my clients offer.

Now you’d think that the subject lines would be really important here, since these contacts have never heard of my clients before.

Not quite…

Right now I have one test running with two completely different subject lines—the A variant is getting a 68% open rate, and the B variant is getting a 67% open rate.

With optin email lists, what I’ve seen is that open rates tend to vary plus or minus about 10%.

So if your open rate averages 20%, an attention-getting subject line might bump it to 22%, and a really poor subject line might depress it to 18%.

The takeaway here:

Because a good email list is by definition already “sorted,” the subject line doesn’t swing the results like you might expect.

That’s not to say that the subject line is irrelevant—it still deserves some thought.

Tomorrow I’ll share some guidelines that I’ve found helpful in crafting solid subject lines.

Related posts:

  1. Guidelines for subject lines Yesterday I mentioned that subject lines are NOT headlines in the classic sense. My first subject line guideline reinforces that: 1. Less specific subject lines get higher opens. Some classic subject lines that are hard to beat are very short and vague: “hey” “quick question” “This is ridiculous” These look...
  2. How Sensational Email Subject Lines Can Hurt Your Open Rates Last week an email with this bombshell subject line detonated in my inbox: That time I almost hired a Baby Snatcher…THIS is why recruiters research you I have to say, after years of following the best email marketers in the biz, I’m pretty jaded when it comes to subject lines...
  3. One word Subject lines are important, right? Just switching up the subject line can often swing open rates by a pretty wide margin. Thinking about subject lines in terms of open rates is a trap though. Here’s why: I recently ran a simple test on an email list of around 80,000 subscribers....
  4. How to Skyrocket Your Email Open Rates with the ‘Uncle Sam Formula’ A few weeks back a client emailed me to say how he could hardly believe the open rate on one of the emails I’d written for him. This client has a list that’s normally very active and engaged. But the subject line I wrote for this particular email set his...