Anyone with an inbox (or two or three) knows email marketing is big business. It reaches millions each year with offers for newsletters, exclusive deals and solutions to problems you probably didn't even know you had.
By 2013, the number of email marketing messages sent annually is expected to reach a high of 838 billion, according to a July report by Forrester's Julie M. Katz. Despite the low cost and the potential for high returns, Katz warns that by the end of 2009, consumers will have become increasingly immune to marketing pitches sent by email as a result of the high volume of such messages.
Obviously, this all points to one conclusion: You need to set your messages apart. And one of the best ways to do this is through useful and compelling subject lines. Check out these strategies for success, along with real-life examples of subject lines that spurred audiences to action.
The first two rules any professional email marketer will tell you are this: Keep it short and don't be afraid to use your brand name. Your "subject line" and your "from" line are the only two spaces -- at least for those emailers who don't use preview panes -- in which you get to distinguish yourself and your brand, so get to the point and do it quickly.
During this year's Olympic games, internet marketing company Lyris helped NBC generate its daily email updates. The company quickly settled on the subject line "NBC Olympics: Top Stories," rather than using content from each day's stories. That approach enabled the readers who opted in to the emails to easily locate and identify the NBC messages.
John Arnold, author of "E-Mail Marketing for Dummies" and head of Constant Contact's marketing education division, says IT company Bek received good results with a similarly straightforward subject line. The line read: "Bek Tips: The Business Benefits of VOIP."
Lyris has used the same strategy for its own email marketing. Company director of product management J.D. Peterson says recipients responded better to "Lyris: Newsletter" than the other variations the company tried.
Professional emailers also emphasize the importance of time sensitivity and the need to give users a sense of urgency. Thane Stallings, a senior consultant at Epsilon, says it helps to include "something the consumer needs to do to take quick advantage of information." Coupons, offers for rebates and sale announcements all fall into this category.
Arnold reports that this strategy has proven successful for several of his clients. Scrapbooking site Create My Keepsake sent out a particularly successful email campaign with the subject line "Labor Day Sale -- 20% off coupon inside." The subject line relied on a familiar holiday theme and prompted the audience to open the email quickly.
Constant Contact ran another successful campaign for accessories company Sojourn Bags. Arnold says the subject line, which read "Free Shipping on New Fabrics," highlighted value and "hints at an announcement of new products."
In crafting their subject lines, email marketers should also consider current spam trends and how consumers will view the emails. Spam filters mean death for many marketing messages. Lyris's Peterson advises emailers to spend some time with the spam box before they target the inbox. Of course, messages with exclamation marks and odd punctuation usually make their way to the junk folder -- right alongside adult-oriented subject lines and text touting various medications.
Arnold warns against words such as "free" and "guarantee," as well as the use of ALL CAPS and generic subject lines, such as "Hey You -- Check This Out!" That's why, Arnold says, a campaign by activist group Women Employed found success with a subject line that targeted a specific audience by category and asked that audience a specific question. The line read, "Action Pledgers: Have you done #33 yet?"
Peterson says emailers should also consider what's going on in the world at any given moment. Currently, messages related to the financial crisis in particular and the economy in general are likely to get snagged by spam filters. Even legitimate pharmaceutical sales messages should receive careful vetting, Peterson says.
"Even if you truly sell Viagra, putting that in your subject line, you're still going to end up in the spam filter," he says. Similarly, for client GameLink, which provides adult movies and videos, Lyris recommended the demure "GameLink: 3-day Secret Sale."
The way consumers view their emails should also influence the way marketers craft their messages. Although many marketing experts suggest sticking to a 30- or 40-character subject line (because those are the maximum characters displayed by common email providers such as Yahoo and Hotmail), they also point out that users of BlackBerrys and other mobile devices can only see 15 characters of a subject line. That's another reason to have your brand name up front.
VerticalResponse CEO and founder Janine Popick recommends mixing graphics and text in the body of an email because the text will show even if the email client blocks the images. For a recent campaign for Pet Camp, a pet boarding company in San Francisco, Popick advised the client to include a hosted version of its email for customers whose email client mangled the initial message.
The truth of email marketing is that no single approach works for all clients. Purchasers of GoodNites, a Pull-Ups diaper product, tend to respond to longer-than-average subject lines, says Epsilon's Stallings. In addition to varying length for niche audiences, it's also ok to be boring, says Peterson (See: Lyris: Newsletter).
Depending on the audience, keywords such as "tips," "tricks" or "secrets" can also work well, says Stallings. He recommends looking to magazine headlines for guidance for subject lines that work, such as "9 ways to cut your electricity bill" or "Fall fashion."
Constant Contact's Arnold recommends that marketers carefully consider their audience when determining email frequency. If your marketing message happens to revolve around the weather, then you can probably justify sending out a daily email. If you're a stockbroker, he says, you can even get by with two emails a day -- as long as they're short. But if your content doesn't specifically dictate a frequency, then you should probably only contact your audience on a monthly basis.
Arnold also advises marketers to categorize and subcategorize their lists. For example, by tracking clicks, a marketer targeting consumers about vacations could determine whether an email recipient is interested in singles vacations, couples vacations or family vacations. The marketer could then better determine who to target with the offer for a Disneyland vacation and who might be more interested in a dating cruise.
Along the same lines, Arnold points to a successful campaign by Boulder Arts & Crafts Gallery that used the subject line "In Store Coupon -- Today Only." That campaign worked because it segmented the audience into online and in-store shoppers, thereby increasing open rates among in-store-only shoppers. The "today only" component of the subject line helped add urgency, Arnold says.
Believe it or not, going negative can also bring an increase in readers. "We're sorry to have to say goodbye" got a 21 percent open rate for one Lyris campaign, while "Take action to keep receiving Intevation Report email tips" and "A better Intevation Report is just one click away" both ranked significantly lower.
Then again, going positive can work, too. Ryan Buchanan, CEO at eROI, found that "Want Fresh Email Campaigns That Increase ROI? Talk To Us Now" brought both significantly higher opens and clicks than the more negative "Is Your Online Marketing Stale? We'll Show You How to Make it Fresh."
In all cases, the best tool for honing in on subject lines that work is testing. Lyris's Peterson often uses what he calls the "wife test." He'll take three subject lines home and show them to his wife, another family member or a friend. The email they open first is the one he'll often use.
For a more scientific approach, Return Path spokesperson Tami Forman recommends using a larger sample size. Choose two subject lines and send each to a portion of the emails in your database. Go with the subject line with the best response rates.
Leah Messinger is a freelance writer.