16 Tips on How to Write Email Subject Lines that Compel Readers to Open and
Read Your Email

"Order: ABC12345 for "YOUR NAME"

Have you ever received an email subject line similar to the above?

I've been getting them sporadically for a while from the same online marketer.

I suppose the rationale is that somehow I will think that it’s an actual order waiting for me to magically claim for free.

Someone must be opening these emails because he keeps sending them out. But in my humble opinion, it's a substandard attempt at a subject line. It makes me feel like I'm being tricked. Plus, it makes a promise I know won't be fulfilled.

So what are the elements of a good email subject line?

That's the question I'm going to take a look at today, starting with the main three options you have when writing an email subject line:

  • You can make an announcement or relay important news to your reader. Example: Launch date for iPad 4 Announced.
  • You can pique your reader's curiosity to the point where they're compelled to open the email. Example: How studying Marilyn Monroe's life can help you become a better fiction writer.
  • You can directly tell your reader how they will benefit from opening and reading your email. Example: Eight tips that will help you get more done in less time.

Keeping the above three main categories in mind, here are 16 tips on how to write an effective email subject line for your clients:

  1. Your subject line should describe the subject of your email – This is of paramount importance. If your subject line doesn't reflect the content of your email, you risk creating a huge disconnect ,which could result in your reader unsubscribing or deleting your emails without reading them.

  2. Keep in mind that people don't like to be sold – Don't make the subject line "salesy," pushy, hype-filled or unbelievable. Subject lines like "Make $45,000 in the next 24 hours" and "$35,000 every week for life guaranteed" will most likely be ignored. Remember Michael Masterson's first rule of selling: people don't like to be sold. They love to buy, but they want it to be their decision. According to Masterson, successful marketers disguise their sales pitch as valuable content.

  3. Keep them short and sweet – The general rule seems to be that your subject line should be 50 characters (or less) including spaces. The rationale behind this is there is only a certain amount of space available for email subject lines. I use Gmail, though, and it's not uncommon for me to receive emails with subject lines of 80 characters (or greater) with the entire subject line being readable in my inbox.

    Here's something to keep in mind, though. The 2011 MailerMailer.com Email Metrics Report found that subject lines 35 characters or less received 52 percent higher open rates.

  4. Remember "The Power of One" – Focus on one benefit, news item, announcement, or curiosity. If you need a refresher on the "The Power of One," click here to read Michael Masterson's article.

  5. Use a consistent and reputable "from line" – The name the email is sent from is a big factor in determining whether or not your email gets opened. The "Order: ABC12345 for “YOUR NAME" marketer has a habit of varying the "from line" of his emails. This can be confusing to your reader, causing him to not open an email because he's not sure who it's from. So be consistent with your from line and chances are your readers will reward you for it.

  6. Add urgency – There are two main ways to add urgency.

    You can use a deadline. Examples: "Last chance to save 40 percent" and "Only four hours left to save 63 percent on customized spa treatment."

    Or you can use scarcity. Example: Only 17 tickets left to Funtasia 2012 …

  7. Avoid CAPITAL letters – Wherever you use them, writing in all caps is usually considered shouting. Plus, they make the text harder to read.

  8. Don't use exclamation marks – They give your subject line a "spammy" look and feel.

  9. Don't avoid the word "free" – In a 2008 blog post, master copywriter Bob Bly addresses this very issue. He talks about a successful information marketer, BJ, who warns not to use "free" in subject lines as it triggers spam filters.

    However, a respected Internet marketing consultant, AA, recommends using the word "free." AA says, “FREE can and does work … in fact, most of our clients have at least one control subject line with FREE in it.” He then gives the example of a list brokerage who did an A/B split test with 2 subject lines: (a) “Boost sales, increase profits, and expand market awareness” versus (b) “FREE Direct Mail Encyclopedia.”

    The “FREE Direct Mail Encyclopedia” generated 25 percent more click-throughs than (a).

    The conclusion being that the increased response produced with a free offer far outweighed the negative effect on clicks caused by triggering spam filters, resulting in a net click-through rate gain.

  10. Consider using personalization in your subject line – Does sending an email with the subject line "Sarah, are you looking to create a residual income stream?" garner a better response than "Are you looking to create a residual income stream?"

    It's a great question. In a 2010 study, GetResponse.com analyzed over 53,000 unique messages sent from GetResponse accounts between September and December 2009. They found that emails with personalized subjects averaged 26 percent higher open rates and over 130 percent higher click-through rates (CTR) than emails without personalized subject lines.

    But here's the bad news.

    The same stats showed that email with personalized subject lines averaged 26 percent higher complaints and over 71 percent higher unsubscribe rates than emails without personalization.

    So what's one to make of this?

    It would seem that when people see their name in a subject line, they may think it's just another spam message. However, if they recognize who the email is from, they are more likely to click and open your email. So whether personalization works, first and foremost, depends on the relationship you've established with your list.

    Having said that, MailerMailer.com came out with their Email Marketing Metrics Report, which was based on over 900,000,000 email messages. Here's what they found:

    1. Emails that had no personalization in subject line or body had an 11.8 percent open rate;
    2. Emails that had the message only personalized had a 12.6 percent open rate;
    3. Emails that had the subject line only personalized had a 6.7 percent open rate,
    4. Emails with both the subject line and message personalized had a 6.9 percent open rate.

    The above findings would seem to indicate that personalizing your subject line actually reduces your open rate.

    The bottom line, though, is to test it out for yourself to find out what works for your client’s list. Do an A/B test, sending out an equal number of emails with the subject line personalized and not personalized, and then compare open rates.

  11. Give your reader a reason to open your email – Don't start your subject line with "Hello" or "What's up?" or "Hi there." They say nothing and give readers no reason to open your email.

  12. Should you use a question as your subject line? – Asking your reader a question is a great involvement device. Bob Bly recently sent out emails with the following subject lines to his list:

    Is hard work necessary?
    Do you know these response-boosting secrets?
    How many web sites do you need?

    All three of them do an excellent job at making the reader want to open up Bob's email to find out the answer.

  13. Start your subject line with a number – People love lists of things that will benefit them. Starting your subject line with a number is usually a sure winner. Examples: "Six ways to make chicken more delicious," "Five unlikely uses for mayonnaise," "Eleven secrets on how to live longer, " and "Twelve ways to skin a cat without hurting the cat."

  14. Study other subject lines – Subscribe to a variety of e-newsletters and monitor what works and what doesn't. If a subject line piques your interest, make note of it. If you see a similar subject line several times, you know the marketer is seeing good results and you should model your subject lines after it. Also study newspaper headlines. They generally do a good job of highlighting a story's most important fact in limited space.

  15. Distinguish between a newsletter issue and a promotion – To make sure you don't confuse newsletters with promotions, put the name and issue of the newsletter in your subject line and/or from line.

  16. Do ongoing tests – If your client has an email list of 20,000 names and you have two subject lines you're considering, you could do a test a couple of days before the email goes out. Send the email with the one subject line to 100 names and the other to another 100 names, and then gauge the response. This might seem like a lot of additional work, but if it boosts your open rate even by a couple of percentage points, it will be worth it.

There's another important lesson from the "Order: ABC12345 for “YOUR NAME" marketer's emails that’s a huge factor in how many of your readers click and read an email when it lands in their inbox.

You see, most of his emails contain only a few words.

Here's what was included with the latest "Order: ABC12345 for John" email:

"As promised, here's the special access to your download. This expires at midnight."

Besides "Hi" and "Bye," that was his entire email.

No mention of the benefit I'll derive from clicking his link. And no direct connection from the subject line to the content of the email. He offers up no real information that will make me a smarter, more profitable marketer. He has given me no reason to trust him.

So the first thing you should do to make sure your emails get opened is to consistently deliver good and worthwhile content to your readers.

If you do that and keep all or some of the 16 tips in mind, you should have no problem increasing the open rate of the emails you write for your clients.

The Professional Writers’ Alliance

The Professional Writers’ Alliance

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Published: February 20, 2012

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