12 Subject Lines That Worked (and 4 That Didn’t)

To Website Design Customers

These are subject lines that I’ve sent to my customers for my website design company. The business builds marketing funnels using WordPress websites for businesses that sell to other small businesses. It’s a relatively small list, around 100 subscribers, but at least half are customers and most have maintenance plans with me.

Open rate is how many people opened compared to how many emails were delivered. Click rate is how many people clicked compared to how many emails were delivered. I’ve made the subject lines anonymous, and also removed anything too specific. If you want to take these subject lines for your business, that’s fine with me.

High Open

Not spending money here might be killing your business:

  • 50% open rate
  • 0% click rate

Ok, bit of a disaster this one. The subject line works because it’s pretty sensationalist. Killing my business?! I need to check this out!

However, it’s clear that the copy of the email didn’t deliver something that resonated with the reader. Hence, a lot open rate. Maybe if I could back up the subject line with copy and a blog post that delivers what the reader expected.

High Click

Here's your free gift

  • 46% open rate
  • 18% click rate

So first off, the open rate is pretty high AND the click rate is high. This is because readers from the day before.

The clicks are high because the subject line delivers exactly what’s inside the email copy.

High Revenue

Does your business qualify for UNLIMITED WordPress help?

  • 40% open rate
  • 13% click rate

This email was selling maintenance and care packages and you better believe that it got read. Not only that, I had someone call to buy within the first hour. In total, this was sent to roughly 60 people. Some customers, some subscribers. Of the 8 that clicked, 6 bought and all 6 are still with me.


Help is at hand for your social media

  • 35% open rate
  • 5% click rate

This subject line was a bit of a disaster because the product that this email is promoting is OUTSTANDING. The copy is good and the subject line gets opens. Yet, I generated literally no sales from these results.

To Other Website Designers

These emails come from a business that teaches WordPress businesses how to build and sell marketing funnels and automation to their customers. It’s a VERY specific audience that is sent marketing, sales and value emails every week. There are approximately 1500 subscribers on the list, with roughly 10% being customers.

High Open

How would I fill in all these emails?

  • 80% open rate
  • 26% click rate

I loved this email because it was launching my YouTube channel. Email marketing is something that my subscribers love help with, from me. The subject line screams mystery and intrigue as first it asks how I would fill in emails, but also, what am I talking about? What does filling in emails mean?

What it delivered was me filling in email copy blanks that they had already received. Talking through the process of writing compelling email copy.

High Click

This timeline infographic shows exactly WHY you shouldn't do a cheap/free WordPress website:

  • 72% open rate
  • 46% click rate

This might be the perfect subject, email and content combination. The subject line says what they’ll be getting. There’s some intrigue as to WHY you shouldn’t do something and it’s relatable because everyone has the problem of free/cheap websites.

The subject lines promises something interesting, the copy shows that it’ll solve a problem and the content itself is easy to read.

High Revenue

  • 27 pre­written emails – AVAILABLE NOW
  • 45% open rate
  • 17% click rate

This was a straight up sales letter. Despite the subject line saying ‘available now’, there wasn’t any lead up to selling these. The product is 27 pre­written, fill in the blanks, white label emails that they can use. It was between $19 and $89 and of the 17% who clicked, pretty much everyone bought because they knew what the price was and what they’d get before they hit the sales page.


I’ve made Instagram valuable for you:

  • 30% open rate
  • 3% click rate

Ugh, I cringe when I read this email. The subject line obviously works as it had a pretty high open rate. But the email DID NOT deliver what they wanted. What was I talking about? It was about how I was now on Instagram, which makes it valuable for the reader.

I know, how incredibly arrogant. I shudder when I read that (it also had the highest number of unsubscribes).

Mike Killen's Blog

Finance Based Business to Consumer Customers

My finance customer is a US based business that sells a consumer financial product to families and individuals. The primary ‘hook’ is that you can protect yourself, your finances and assets if you pick up this product.

High Open

[Cost of other service] too high?

  • 17% open rate
  • 10% click rate

This was a super simple email designed to ask if they were paying too much for a competitor’s product. Because it was from our recognisable name and we used a common service name or competitor name in the subject line, people wanted to know what we could offer.

High Click

Is [product/service] stressing you out?

  • 16% open rate
  • 15% click rate

Another recognisable name, being asked if it’s hard work. Often, common services that we use have problems and missing links that make them hard to use. We were trying to capitalise on that. What helped is that the copy in the email lead readers back to a page that told them how to solve that headache. Problems that people can identify with are the easiest to understand too.

High Revenue

Lower your [service] cost TODAY:

  • 3% open rate
  • 2% click rate

This email was delivered to readers if they had clicked on either of the previous two. In fact there were 11 emails in total and this email was the first sales letter to buy the product that we had talked about in previous emails and posts.


Lower your [service] cost TODAY:

  • 0.2% open rate
  • 0% close rate

Nope, that’s not a typo – it’s the exact same subject line as the one above. However, we sent it to the wrong list (over 18000 people) that had NEVER received the previous emails and weren’t even in the same situation.

It’s like being sent an email selling car insurance when you don’t even own a car. My big takeaway? It doesn’t matter how awesome your email subject line is, sent it to the right list.

Marketing Based Business to Other Business Customers

This customer sells marketing and lead generation and financial, insurance services to other businesses. Their customers are typically 5­20 in size. The lists for this customer are MASSIVE (25000, 14000 and 18000) so the numbers are much lower, but physical opens/click are big.

High Open

You began the sign up process but didn't complete it.

  • 40% open rate
  • 6% click rate

Bit of a cheeky one this, this email was sent to customers who signed up but DIDN’T complete the process. The reason it was such a high rate is because customers already had a relationship with us. To be honest, this particular email didn’t get many people to sign back up, but it helped plug a leaky funnel somewhat.

High Click

Agent makes $32,000 in ONE week off other people's [problem]

  • 18% open rate
  • 13% click rate

Ok, a little ‘sales sleaze’ maybe – but we were selling marketing services to sales people. So they love 2 things. Money and numbers. If you can put an actual numerical result in your subject line and show proof, you’ll get opens and clicks.

High Revenue

Here's your chance ­ Use the [Problem] Nightmare to up your game

  • 7% open rate
  • 3% click rate

This email was delivered to customers that knew they were looking for our product. What we were trying to do is show them how to profit from a common problem that their customers had. Let this be a lesson to you.



  • 10% open rate
  • 0.2% click rate

Let this be a lesson to you. NEVER use a fear-based, sensationalist subject line followed up with what is clearly a sales letter.

Also, we used the term news flash because we’re trying to be funny. The problem is that people interpreted that as genuine news and were VERY annoyed when it was clearly a tactic just to get them to open.


So what have we learned?

  1. Always backup your subject lines with copy/content that they expect to see
  2. Interesting and explosive subject lines WILL get opened – but read rule 1.
  3. You can use intrigue, numbers and a promise as a basic subject line formula.

Have you experimented with subject lines before? What’s worked for you? Let us know in the comments below if you’re going to take any of these (it’s ok I won’t tell anyone).

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Mike Killen

Mike just wants to help funnel builders sell more marketing funnels to customers. He runs sellyourservice.co.uk which coaches and trains businesses on how to find more customers and sell funnels to customers. Since 2015 when Sell Your Service started, Mike has trained over 500 funnel builders to find more customers and sell more funnels. Most recently he helped generate $100 000 in 30 days using a basic marketing funnel for a customer. If he’s not writing blog posts or creating training. He’s training at Muay Thai or surfing.

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