What if you could make a slight change to one of your emails and get a 20% lift in opens or a 10% increase in sales? You would do it in an instant. But how do you know what element to change?

That's where testing comes in. Email marketing makes it easy to quickly test important elements of your email - at very little or no extra cost. With testing, you can find out what factors influence the success of your email. Follow these five steps to create an effective, measurable test.

Step One: Decide what to test

Because testing with email is so easy, it's often tempting to test many elements all at once. You should start by testing just one. Why? Because if you test more than one element in the same email, it is challenging (and sometimes impossible) to determine what exactly influenced the response. Here are some easy and telling tests to start with:

  • Subject lines. Create two different subject lines for the same email communication. For example, a boutique owner just added a home and garden section, and she wants to get the word out to her customers. Here are the subject lines she'll test.

― Subject line 1: New! Home and garden section added
― Subject line 2: Get what you need for your home and garden
  • Long versus short copy. Is less really more? Create a shorter version of your current newsletter with teasers and links to your website. Or create two versions of a promotional email. Keep one very short and to the point and make the other a little longer by adding useful information.
  • Special offers. Create two different offers. For example, an online bookseller wants to get rid of last season's best-sellers. He sends the following offers to see which one gets a better response:

― Offer 1: Buy 3 books and get 1 free
― Offer 2: Buy 3 books and get free shipping

Other tests could include the time of day or day of the week you send, with an image or without, types of call-to-action, and the placement of a call-to-action button or link. You are sure to come up with other areas you would like to test as well.

Step Two: Decide how to measure success

What will you measure to determine success? Possibilities include website traffic, response to an offer, sales, opens and click-throughs. Whichever you decide on, be confident that you can attribute an increase (or decrease) in the area you measure directly to the email you send. The easiest place to start is with your email campaign opens and click-throughs - data that your email marketing service provider makes available to you.

Step Three: Decide how to divide your email list

When it comes to choosing the recipients of your test, you have two options. You can either split your entire list in half and test one against the other, or take a random sample and do a pre-test.

A pre-test is an excellent way to find out what works before sending the email to your entire list. This knowledge can greatly improve your overall response rate. It also protects you from sending a poor performing email test to a large portion of your list - and wasting your efforts. To pre-test, choose a random sample of 100 people from your master list, then split that in half and send each half one of the two test campaigns.

Step Four: Test, measure, and declare a winner

Once you have everything ready, send your test emails. The great thing about email is that you get your results quickly. Within a 24 to 48 hour period you will know which email communication got a better result. (It takes weeks when testing with direct mail.) Declare your winner, send that email to the remaining members of your list, and watch the results come in.

Step Five: Keep it up

Make a guess as to which version will win before you send, and see if you are right. What's amazing about testing (and what proves its incredible value) is that many times the results are not at all what you expect.

Let your customers, clients or members tell you, through their actions, what they respond to best. This method is an excellent and trustworthy way to improve your emails. Test often!

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.