The Best Email Subject Line of All Time

“You are invited”

That subject line lives in infamy as the single greatest subject line ever written. Why? Did it generate the most opens? Did it generate the most sales or highest response rate?

The why is the most important part. A subject line is meant to do one thing. It’s meant to get people to open the email.

So what makes someone open an email? What makes “You are invited” such a great subject line?

  1. It grabs attention
  2. It stands out from all the other subject lines I see in my inbox
  3. It makes me ask a question – what am I invited to?

Because it stands out and captures my attention, it already has a better chance than most emails do of being opened. But it really hooks me because of the information left out. I have to open it to find out what I am invited to.

So it’s a winner.

Does that mean it will be a winner for you?

Absolutely not. The idea of a universal subject line that will outperform all others is insane. Like so many other things, it depends on your company, your products, your offer, the content of the email, and the nature of your consumers.

The point is this, understanding what your subject line is there for is the first step in crafting the perfect subject line for every email you send out. Hook your readers, offer value, stand out from the crowd, and give them a reason to open your email and read it.

What’s your best subject line of all time?

What’s Your Inbox Worth?

“It’s free, we just need your email address.”

We’ve all seen and heard this offer made. Something like a whitepaper, or ebook, or service is free – but it will cost us our email.

It’s time marketers recognize that email addresses have value. We already know they have value to us, as marketers, or we wouldn’t ask for them. We ask for them because we are going to use them for something. We’ll either sell them to a third-party, or use them to stay in touch with those customers and try to sell them something later.

But we completely ignore the fact that email addresses have value to the person giving them up. Getting permission to enter their inbox is worth something.

Recognize that exchanging an email address is a transaction, just like exchanging money.

So what?

  • Make sure you offer enough reason to get that permission
  • Make sure your reason is clearly explained
  • Make sure you deliver on any promises you make as they relate to the customer’s email address
  • Continue to earn your right to their inbox over time (because access can be turned off anytime)

Email addresses are not free. It’s time we stop treating them like they are.

A Year in Email Subject Lines

A post for all the email marketers out there.

It’s the start of a new year. Are you optimizing? Are you redesigning?

Email is one area where it pays to never be satisfied. Your current results might be as good as you’d hoped. You might have had higher open and click through rates in 2015.

But 2016 is a new year with new possibilities. And now is the time to be testing and learning more about your subscribers.

The best way to prepare for the future might be to look at the past. Over the last week or two, I went back over all the emails I sent in 2015. What I wanted to know – how did the subject lines impact open and click through rates?

You can do this too. All you need are the subject lines, the total emails sent, the opens and clicks for each email. List them all in one excel file and then group them in different ways.

  • Does the length of the subject line impact results? What’s the ideal length of a subject line?
  • Does putting a special offer in the subject line improve results?
  • Does personalization improve open rates?

Those are some of the questions I asked, and you can ask them too. You might have other questions you want to find the answers to.

Some of what I learned:

  1. For one brand, shorter subject lines worked (less than 45 characters). But for another, the length of the subject line seemed to have no impact.
  2. Including the phrase “Special Offer” at the front of subject lines lifted open rates higher than actually including what the offer was, e.g. $100 off.
  3. Including the subscriber’s first name in the subject line led to better open and click-through rates.
  4. Adding special characters, like brackets or exclamation points, into the subject line actually hurt the performance of those emails.

I’d be curious to see what you learn when you look at 2015 email results. Then you can use those learnings to optimize your emails in 2016.

Guest Post - Old School Marketing for New School Marketers


My name is Tom Buckland and I’m an SEO freelancer. With that one statement, you probably already have a grudge against me.

The truth is the SEO industry gets an extremely bad name for itself – with the constant cold emails that business owners receive and the horror stories of client websites dropping from Google. There is good reason why the average business owner automatically takes a defensive stance when an SEO / digital marketing guy introduces themselves.

But, like a lot of industries, when direct marketing is done correctly, there is no reason why you can’t land clients in even the toughest industries.

This article is about a case study / client generation strategy I ran for my seo company HQ SEO.

The Strategy

Our strategy was simple. We would use direct mail and email to pre-qualified prospects. I would personally write the copy, a skill I learned from 2 business books, which I’d highly recommend to anyone who owns a small business, “Guerrilla Marketing” and “Words That Work”.

Stage 1 - Create a list of pre-qualified prospects. For anyone interested in replicating this process you want to create a list of business owners who are already actively marketing their business. This is essential, as dealing with business owners who don’t understand why they should be marketing is not a conversation you want to have with someone when you are trying to close them.

To get the list of prospects, go through your local magazines, newspapers, online classified ads, and most importantly, search in Google to see the businesses using AdWords. Find businesses that are already spending money on advertising or marketing. These prospects will be 100 times easier to eventual close than ones that can’t see the value of online marketing at all.

Stage 2 - Once you have your list of prospects, the next step is to decide on a contact medium. I’m not one for cold calling, which left me with either direct mail or emails. We tested both, but play to the strength of your business.

Stage 3 - Write your copy. There are a number of aspects that change depending on who you’ll be emailing, but below are a few keys to remember when writing copy, for both email and direct mail.

  1. Keep it on 1 page.
  2. Keep it short.
  3. Don’t add fluff.
  4. Make it personal.
  5. Make it relevant.
  6. Say “you” and “your” more than “we” or “I”.
  7. Use imagery.
  8. Have a catchy and relevant headline.
  9. Include at least 2 calls to action.
  10. Describe the benefits.
  11. Don’t add irrelevant points.
  12. Use simple language.

If you keep to all of these rules you should be able to have a piece of copy that you can use as an outline when you send to your prospects.

A side note on personalization: We contacted close to 800 businesses in this period. 100 through direct mail and 700 through email. Ideally we would have researched each individual and business separately, but that would have taken forever. Instead on our emails we used a semi-personalized script, repeating the business name and owner’s name, as well as including an image relevant to their business. In some cases this was a screenshot of their current rankings, in other cases it was a picture of their website discussing potential redesign elements. Either way, to the prospect it would have felt personal. This is the key.

Stage 4 - Delivery. If you are using email, then your delivery medium is pretty simple, you press send. But if you are using direct mail and physical letters, there are 3 key elements to remember:

  1. Hand write the envelope. This looks more personal and not mass-generated.
  2. Use headed paper. Looks professional and costs pennies!
  3. Use a white, standard envelope. Again very professional and also the cheapest.

The Results

In total we sent 700 emails. Managing to increase our open-rates to 1 in 3. The click through rate of 14% on the emails was again lower than we wanted but all in all gave us 32 “bites”. Screenshot of our email stats are below.

Of those 32, 18 prospects went on to contact us for the consultation / audit. Although this number was far higher than the results generated in the direct mail testing, we also noted the style of response was negative and short. Such as the one below. 

And although the stats, volume and personalization all came together quite nicely, we concluded that people simply were more negative when they receive a semi-cold email, than they are when they receive a semi-cold letter. The physical aspect and cost might have something to do with it, or (and what I believe) the nature of the industry plays a big role.

A side note on the industry: If you’re in digital marketing, it’s better to do what other marketers and businesses are NOT doing, which is sending a physical letter.

The direct mail results were more difficult to calculate. But assuming 90% of mails were delivered and opened, we can say approximately 6% of individuals took action. This lead to 5 individuals making direct contact requesting a proposal / consultation. 2 of which came on to be clients.

Time, Costs & Conversions

Direct mail results

Research time: 50 hours (yes it really did take this long!)

Writing time: 15 hours (Semi-personalized script made this easier)

Printing/Writing and mailing: 5 hours

Cost: approximately £100.

Results: 2 signed clients @ £300 / month.

Average time of a client is around 6 months. Meaning our total earnings for the campaign were £3,600.

Although this is not all profit, the ROI was incredibly high. This is also a technique I highly recommend for start-ups, as it’s extremely time heavy with the research and writing, although relatively cheap compared to other start-up marketing techniques.


Research & writing time: 60 hours

Costs: £640 (Wages + Email tracking software)

Results: 1 signed client @ £400 / month.

The email outreach did generate more “bites” but the eventual traffic was a lot colder and hence more difficult to convert leading to a lower ROI. The eventual conversion rate was only: 700/1 = 0.14%.

Thoughts and Advice

If I had to give one piece of advice to someone looking to generate clients in this way, it would be this - Don’t get bogged down in the numbers or the methods. 10 highly personalized direct mail pieces or emails, to warm pre-qualified prospects is better than 10,000 cold ones. And taking action is better than 50 hours of research! So although testing is a key to success, remember you can test with extremely small volumes and refine your copywriting and data so that when you do run larger out-reach campaigns, they will be extremely profitable for your business.

What is CTR?

CTR stands for Click-through Rate, which is a common term in online advertising, one every marketer should be familiar with.

It has several uses, but in call cases it refers to the percentage of people that “click” on something after seeing it. For banner or search ads, it’s the rate of clicks per impression served. For email, it’s the percentage of recipients who click on one of the links provided in the email.

It is almost always expressed as a percent. So the formula we use to calculate click-through rate is as follows:

CTR = Clicks/Impressions x 100%

Why is click-through rate important?

In online advertising, CTR is a common metric marketers use to determine the effectiveness of an ad. The more people we get to click on an ad, the better, generally speaking. So our goal is to test out new ads, with better copy or designs, in an effort to improve the CTR.

In email marketing, CTR is a common metric marketers use to determine whether or not an email generated sufficient response. A higher CTR signals more interest from subscribers, more people visiting your site or entering the sales funnel. We test new emails, with better copy or designs, to increase CTR.

Understanding CTR and how to measure it is important if you want to succeed in the digital advertising world.