Email Testing is one of the easier Testing options – and it can be the most cost-effective. You want to test the elements that have the biggest impact on email response. That includes:

  • How the names were selected
  • Subject Line (which determines whether your email is viewed)
  • Offer
  • Overall copy with your key benefits
  • Length of message
  • Format of the email – personal email vs a promotional approach with an image.

You also want to test big differences in each of these elements to find a significantly better version.

To track results of ech version, create a unique UTM tracking code for each version and email the two versions at the same time (as much as possible).

Review Unique Clicks/Delivered, Leads/Delivered, or Sales/Delivered for each Campaign version to pick the winner.

In Google Analytics 4, under Life Cycle, Acquisition, select Traffic Acquisition. In the Session Default Channel Group column, click the + and choose Traffic Source, First User Campaign.

Get ready to dazzle your boss with your marketing smarts!

To test list segment vs list segment in email

Create one list with your segmentation criteria and create a second list with different criteria (or choose names with no specific criteria but from the same general population, like “customers.”)

  • Keep everything else the same between the Lists: use the same email Subject Line, Offer, email message (copy, message length, Format), and Landing Page
  • include the UTM tracking code (one for each version) in your action link

To test Subject Lines

  • Keep everything else the same between versions (same List, Offer, copy, message length, Format, Landing Page).
  • Split the email list into as many groups as you have Subject Lines to test. (You want to create random groups as much as possible.)

Compare Open Rate, Unique Clicks/Delivered, and either Leads/Delivered or Sales/Delivered to see which Subject Line was best.

It’s common to find a Subject Line with a better “Open Rate” but a poorer Conversion to leads or sales. So, be sure to follow your results through to leads or sales when possible.

To test Lead Generation Offers

Everything about your email should focus on the Offer. The steps below assume you want to promote each Offer in the Subject Line and body copy.

  • Create a different Subject Line and email copy for each Offer. Each email version will contain a link (with UTM tracking code) to a different Landing Page (one per Offer).
  • List, message length, and Format of the message should remain the same between versions.
  • Create as many random email groups as you have Offers to test.

Compare Unique Clicks/Delivered and Leads/Delivered. You’ll conclude that one Offer, its Subject Line, copy, and Landing Page generated a higher percentage of leads than the other one.

Because the Offer, Subject Line, and copy all change between the email versions, you won’t know if any difference in response was due to any of those elements separately.

To test sales Offers

  • Create a different Subject Line that promotes each Offer and modify a portion of the copy that pitches the Offer. (You’ll likely need to include a particular “bonus code” in each email.)
  • Use the same Mailing List, general message copy, message length, Format, and Landing Page.
  • Split your Mailing List randomly into as many groups as you have Sales Offers to test.

To test overall message

  • Use the same list, Offer, Format, and Landing Page.
  • You’ll have two different messages, and you may want two different Subject Lines.
  • Create list groups for as many message versions as you have to test.

To test length of message

  • Create a long version of your message, and a summary version of the same message – using the same headline, lead sentence, emotional driver, and key benefits. (One will go into more detail, one will be more of a summary.)
  • Use the same list, Subject Line, Offer, Format, and Landing Page.
  • Split your list randomly into two groups.

To test message Format

  • Create a personal message approach and a more promotional approach of the same message. (Or you could test two different layouts or designs.) In this case, your headline, lead sentence, and the way you write your copy may all be different between the versions, but you should have the same benefits in the same order in each version.
  • Use the same Mailing List, Subject Line, Offer, and Landing Page.
  • Split your Mailing List into two random groups.

To test different images in a “postcard” format

If you’re selling a product via ecommerce, your email will likely feature an image of the product prominently, in more of a postcard format — image followed by copy and action button. You may want to test different product images in two different email versions.

  • Use the same list, Subject Line, Offer, message copy, message length, and Landing Page. Split your list into two or more random groups to test different product images.
  • If you want to test two completely different products, use the same list, Offer, and message length. In this case, you’ll conclude one email did better or worse than the other.

What if your email quantities are small

I have a client that markets in different states at certain times of the year. Many of those states have fairly small email lists, so testing for a particular state may not yield results we can rely on.

We use the same email series of messages (modified with each state’s details) across states, and then we review results quarterly. The quarterly totals are large enough to give us statistically significant test results. We identify the winning versions, and then use them for the next state’s campaigns.

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