Man using smart phoneCreating compelling subject lines is difficult, especially when you have to come up with fresh ideas every week. What’s going to get the attention of your audience? What will make them open and click? And how can you create a snappy subject line that does all that and also manages to set up the right expectations for what people will find inside? It’s no wonder so many marketers try to find hard-and-fast rules for what to do (and not to do) when writing better subject lines. But those rules are changing all the time.

For example, as an email marketer, one of the most common questions I get asked is, “How long should subject lines be?” It’s a great question. Type it in to Google and you’ll get millions of search results. There are a lot of studies – and plenty of opinions – about how long the “ideal” subject line should be. My opinion is simple: What does your audience respond to? Have you tested long versus short subject lines? How many times? What does the data say? Because it the end, that’s what matters most.

That said, there are some important best practices to keep in mind for creating better email subject lines. Here are just a few of them.

1. Optimize for Mobile

email-subject-lines-mobile-1According to Litmus, nearly half of emails are being opened on smartphones and tablets – that’s a 500% increase in just four years. Mobile email apps display approximately 35 characters of a subject line in the inbox view. Anything more than that is likely to get cut off. Now, your results may vary. Do you know how many of your emails get opened on smartphones and tables? Now is a good time to find out, because shorter is better if many of your recipients are opening your emails on a mobile device.

You’ll also want to optimize the text that’s visible on mobile phone inboxes just after the subject line. It’s called the header or preheader, and if you fill it with copy like “Trouble reading this email? Click to view in a browser,” you’re wasting valuable real estate for potentially half of your audience. Ideally, the email subject line and header should work together to create a compelling message. Save the housekeeping copy for elsewhere in the message.

2. Use Symbols – But Only if Your Readers ♥ Them

Symbols can make an email stand out in the crowded inbox. Some consumer brands like Home Depot can’t seem to get enough of them. It gets annoying because when everyone’s doing it, the subject line doesn’t actually stand out – it just adds to the clutter.


If you do use symbols (and we do, here at Act-On, but generally only to promote the I♥marketing conference, and hey, that’s what it’s actually called) be sure to test them out and make sure they show up correctly. If you don’t, you might get some weird-looking characters that make your message look like spam. (Or maybe the email marketing team over at Pottery Barn has been taken over by the Riddler.)


And indeed, too many smiley faces, even if they show up correctly, could cause readers to flag an email as spam.

3. Make it Personal – The Right Way

Notice that in the example above, three out of five emails are using my name in them. Personalization gets results, so it’s no wonder. But like adding symbols, using a name in the subject line over and over is likely to cause your readers’ eyes to glaze over. So are all those exclamation marks (!!) To be honest, the email I’m most likely to click is from ModCloth. The subject line is funny, it’s low-key, and it’s a reminder that I left that cute swimsuit in my bag and never went back to buy it. Now that’s personalization I can use.

4. Use SHOUTING and Scare Tactics Sparingly

Every once in a while I visit the Rejuvenation web site. I love their light fixtures. I have several. I’m a fan of their bath fixtures, too. Can you tell? Because they’ve sure figured it out.


Actually, this is a great example of a nurture program. They’ve been sending me the “Looking to Update your Bath?” message for some time now. When I finally clicked on it, they provided a free shipping offer. Tempting! Except… I live about two miles away from their store, so it doesn’t really help me. What I don’t like is the fact that they told me it was my “LAST CHANCE!” for “FREE SHIPPING” on one day, and again the next day. Quit shouting at me (and threatening to cut off a deal I’m not interested in anyway) and find out what I really want. (What I could really use is a discount on that $100 towel rack!)

In any case, yes, limited time offers and “time is running out” messages get results, but when you go overboard, your customers stop listening. As for the all caps, well, once again, testing is key. If it works for you to shout at your customers and prospects in all caps, go for it. Just remember that it’s not always the best way to represent your brand.

5. Say Something Once, Why Say it Again?

This reminds me of another thing that drives me crazy – getting the same subject line over and over. Yes, for Rejuvenation, it eventually drove engagement (I finally clicked on it, but only because my old towel bar broke that week.) So, it worked, but only by accident.

To be clear, they did a great job creating an automated program and providing an offer based on the customer interaction. Good work! But don’t send me the same email/subject line combo again and again. Mix it up a little bit. Try a different offer. Try a new subject line. Something. Anything.

The same goes for marketing emails that waste subject line real estate by repeating the From address. If I know who it’s coming from, I don’t need to hear who is sending it again in the subject line. McMenamins, a Northwest brew pub and theater chain, is a repeat offender. They use the same subject line, every month, and they don’t make it informative in any way.


I almost clicked on the one that included the [beta 4] because it was different from everything else I’d ever gotten from them. I wondered if there was an indie rock band out there called [beta 4] I should be checking out. However, it also made me think that it’s possible – just possible – that every month, the marketing team actually tests this subject line against several options (beta 1 through 3, perhaps) and that the generic version always wins. If that’s the case, I stand corrected. Because the data doesn’t lie, and if testing shows it works, it works.

Remember, email marketing is the most effective when it’s tailored to your audience. And subject lines are a great way to tailor your message. But don’t just add some hearts, flowers, and first names to make a personal connection with customers. Understand the devices they’re using, their geographical location, the places they’ve visited on your site, the purchases they’ve made, and what really makes them click, and you’ll be able to get them to open your emails every time.

Once you’ve figured out subject lines, be sure to check out The Amazingly Effective Email Guide to get even more tips for creating successful – and profitable – email campaigns.