Subject lines VI: Final factors

Part I: Length
Part II: Objectives
Part III: Branding
Part IV: Personalization
Part V: Copywriting and inspiration

When sitting down with a subject line to write, most people focus on length and copywriting issues. We've already broadened that scope to include branding and personalization, but what else might be an issue?

What are some final factors that influence those few words that ignite the email experience for subscribers?

Frontloading

Where you can, put your important (key)words at the beginning of the subject line. Apart from any psychological attention-getting impact, many email clients and webmail services limit the display area given over to the subject line.

For example, my Windows Live Hotmail account with the vertical preview pane activated leaves just 28 spaces for the subject line. With the horizontal preview pane, the allocation jumps to well over 100. My Yahoo! Mail account offers 42 spaces. My desktop client 74 spaces in its current setting.

(And two more words: mobile devices!)

If we take our advice on length - as short as possible without compromising on what you want to say - then the subject line structure should be:


So an email marketing newsletter with a key article on subject lines, plus some other news items might look like this:


And a retailer could write:


...rather than...


If the subject line does get truncated, then the more powerful elements are still likely to get seen.

MarketingSherpa recently reviewed a year's worth of their own newsletter subject lines and reached a similar conclusion:

"Sherpa's top subject-line performers showed that pushing the value of a particular newsletter in the first two words was optimal."

Style

Branding subject lines isn't just about putting a recognizable name in there. Your subject line style should match your brand and audience (the two being related).

Experimenting with styles is fine, of course, but take care not to disappoint, disengage, or disenthuse (not a real word) subscribers who signed up with clear brand expectations.

Which is a pretentious way of saying if you're a 250-year old investment bank distributing stock news to retired executives, you might be careful about constantly using subject lines like, "Yo dudes, tech stocks rock!"

Legal compliance

Many anti-spam laws include provisions on subject line content. Check your local laws for details.

The USA's Can-Spam Act, for example, forbids subject lines that are...

"...likely to mislead a recipient, acting reasonably under the circumstances, about a material fact regarding the contents or subject matter of the message..."

What's not spam

You probably read somewhere that there are certain words or punctuation that get an email flagged as spam. And experts regularly publish lists of words to avoid.

Your ESP should provide a spam-checking tool that picks up on such problems. And there are standalone tools that do the same thing, such as SpamCheck or tests built into design testing tools.

The rules on what is and isn't acceptable are in constant flux, but the key point is that anti-spam technologies are not your main worry here.

Yes, many anti-spam software packages and email clients still use subject line content as one element in identifying spam. SpamAssassin, for example, does numerous subject line content tests, which you'll find in this list.

But...the importance of content-based filtering is in decline as reputation based filtering spreads. And your bigger challenge is avoiding the human spam filter: the recipients who use the subject line to judge whether your email is spam or not.

If your email's subject looks like the kind of thing a spammer might write, it stands a good chance of being treated as such.

Which means use your common sense: don't write all in capitals, don't include perverse punctuation or misspellings, no excessive use of exclamation marks, no overhyping the offer etc. etc.

Testing

If you've taken in all the advice and resources provided in this series, you might be forgiven for thinking you have subject lines cracked. I wish it were so, but let me quote Ken Magill in an article on email design:

"As is the case with traditional direct marketing, the most effective subject lines are often not the ones a marketer would predict to win."

Two years ago, MarketingExperiments even tested this belief, getting a marketing audience to predict which of three subject lines would perform best. The result?

"...our survey respondents favored the worst performing subject line."

Just about all the factors covered in the series can do with testing to find the right mix, and Chad White has specific suggestions here.

Much has been written elsewhere on testing, so I would merely highlight three testing issues that are often overlooked:

1. Judge subject lines on the right results.

Many people judge subject lines based on open rates. But an "open" is rarely your end goal.

Compare subject lines based on the results that matter: downloads, pageviews, registrations, sales, order size, conversion rates, whatever your chosen measure of success is.

This is important, because research has shown that very specific subject lines, for example, can lead to lower opens, but more clicks.

2. Test subject lines for each segment

If you segment your list, don't use aggregated results to pick a winning subject line. Instead, test subject lines for each segment.

You may find, for example, that long-serving, active subscribers react best to a simple branded subject line that focuses on recognition, but newer or more inactive subscribers need something more benefit-laden to get them to pay attention.

You might even reverse the concept and consider segmenting your list according to how they respond to different subject lines...

3. Test intuitively

If testing is impossible or your list too small to generate meaningful test results, then cast your eye back over past issues and campaigns. See if you can correlate high open and response rates with particular subject line topics or approaches.

Do any patterns emerge which suggest the kind of copy that resonates best with recipients?

Bonus tips

And to bring all this to a close: here a couple of bonus tips worth considering:

1. If you have trouble getting keywords up front, use the colon trick. Example:


...rather than "How to improve subject lines"

2. Leave trailing dots on your subject line to indicate there's even more in the email than you can reasonably fit into the subject line. Example:

Free shipping on top brands: Calvin Klein, Trussardi, Fila,...

3. If you put a brand, business name or newsletter title at the start of your subject lines, you probably use brackets to distinguish this from the actual subject line content. Consider using different types of brackets or name formatting to stand out a little from the rest.

• [EM Reports]
• \EM Reports\
• {EM Reports}

4. Try a little contrariness

In email, familiarity breeds contentment but sometimes contempt: the same subject line approach might lose its performance gloss over time. Consider doing something different now and then to mix things up and spark a little curiosity in subscribers.

OK, this brings our subject line journey to an end. Any additional suggestions or resources are very welcome: click on that comment button and let me know!

More on subject lines | Tags: email marketing, subject lines

Sign-up for the Email Marketing Reports NEWSLETTER
Twice a month, free, packed with email marketing advice and all the posts from this blog.

Email:      First Name:     
    More info and sample

 via feed | via email | LinkedIn | Facebook

The main website for everything email marketing
Email marketing search engine
Introduction and email advertising basics
Service listings and sources of statistics
Advice on email design and delivery issues

Top 21 email marketing info sources
Outlook 2007 and HTML design
42 HTML email design resources