Just about every client I work with has some sort of email marketing program, and yet what goes into every client’s strategy couldn’t be more different. From clients in the home services industry, to food and beverage and corporate services, the nuances of making effective emails is a delicate process – and even a small change can have a huge effect on your email metrics. Sometimes, the most effective way to find out what’s going to work for your particular business is through trial and error. To try to find those sweet spots for both Roundpeg and our clients’ email campaigns, we conduct what we’ve been calling “split-list tests.” If your email campaign is stagnating, perhaps try some tinkering of your own, and we’ll show you how.

Setting up the test

Let me get one thing on the record before we dive in: I am in no way a scientist and I have only worn a lab coat once (and that was to a Halloween party).

Now that that’s out of the way, the best way to run one of these tests is to split your list into random samples. If you want to be super fancy and exact, you could export your entire list into a spreadsheet, assign each contact a number, and then randomly generate groupings, but that’s not really necessary. We find that splitting a list into two (or more) sections alphabetically gives a good semi-random grouping. An alphabetical sort will also help you control for factors which might influence open rates, such as how long a contact has been a part of your email list, or their average response rate. Also, keep in mind that the more contacts you have in each test list, the more reliable the results you get will be. So if you have a list with only a few hundred names, you may want to focus your energy on building your list before you test different campaigns.

Now that you’ve got your test subjects, you’re ready to experiment. This is the point at which you’re allowed one evil mad scientist laugh. Go ahead, I’ll wait.

Good job! Now let’s take a look at some different parts of your email you can change to see what gives you the best results. Note that when you do perform these tests, you’ll want to change only one of the following components per email. If not, you’ll conflate the results and be no closer to finding what works best than you were from the beginning.


The layout of your email is probably the piece of your test that will show the biggest change in results, and rightfully so as it’s going to be the most difficult to change in a meaningful way. This is where you can go a little wild with your strategy. If your usual newsletter is a smattering of blog excerpts with links to read more, try a more visual approach with images and easily digestible information that more directly invites your audience to click through. Do you usually send out a generic monthly promotion for everyone? Try instead a personalized approach that emulates a personal correspondence, using your contacts’ names and addressing them directly. You’ll know a change in layout is hitting a good spot if you see a spike in clicks.


The primary purpose of your email is to get your audience to click through to your website and knowing what’s going to make your audience click more often is invaluable. I recently did a test with one of my clients lists, one of the only changes I made to the email was an additional click opportunity in the form of hyperlinked text which the original lacked, having two large calls to action in the form of a linked image and a button. Surprisingly, I saw almost double the click through rate, primarily going through that hyperlinked text. I realized that this may have been due to the fact that the age of the audience of this email campaign skewed slightly older, thus they may have more readily recognized a text link than an embedded image.

The lesson here is just like with layouts, your audience may respond differently to different link formats. Running these types of tests will help you find what those strong performing formats are.


Though you may not give much thought about what day of the week or what time of day you send out your newsletter, shifting your send time by a day or even a few hours can have a big impact on how it’s received. Depending on your industry, your audience and more, you may find better results first thing Monday morning or early evenings on Wednesday. Reviewing your open and click rates based on timing will give you a better idea not only when your audience is more likely to look through their inbox, but also when they’re more likely to engage in pre-purchase behaviors.

Subject Lines

You didn’t really think there woud be a blog post about email without talking about the holy grail that is the subject line, did you? Not a chance.

Testing different subject lines at the same time to different groups can tell you a lot more about your audience than just what words look good in an inbox. Whether you highlight limited-time savings on your product, the latest news from your business or a special event you’re hosting soon, what you put in your subject line should always provide something of value. When you split your list and see different open rates with differing subject lines, you’re getting a glimpse into what your audience finds valuable and worthy of their time. That kind of information is invaluable to increasing your conversions to growing your list, and to an overall more successful email campaign.

Though I could go on about different ideas to test in your emails, the long and short of it is that when it comes to email marketing, it’s going to take time and effort to find the most effective strategy, and it can be rough going to find your sweet spot. When you do find it though, you’ll see the real value of email to your overall digital presence.

Email Success