31.03% Increase in Sales by Tweaking the Call-to-action Copy on a Payment Page

Which Test Won Winner Testing Awards 2013The copy you use in your call-to-action has significant impact your conversion rate. In fact, CTA copy is just as important as the button itself. Here’s a case study where tweaking a few words in the call-to-action on a payment page generated a 31.03% lift in sales.

Background info:

Client: WriteWork.com a subscription-based education website for college and university students.

Product: Monthly subscription. First payment $9.90 – recurring payment of $14.95

Page: Payment page.

Optimization goal: Increase number of subscriptions sold.

Payment page with the control CTA copy “Create My Account”

CTA critique:

In my experience, the more relevance and value your CTA copy conveys, the more clicks and conversions you’ll get (watch this video for a full tutorial on writing CTA copy that converts).

The control CTA copy “Create My Account” is relevant, as it adresses the conversion scenario at hand and describes what will happen when you click the button.

It also conveys a certain level of value. As opposed to “SUBMIT” or “Buy Subscription”, it emphasizes the positive aspect that you’re going to create an account, which has an implied value to the potential customer.

Nevertheless, I saw room for improvement and hypothesized that a few copy tweaks would lead to a lift in sales. Firstly, my experience from 4 years of testing CTA copy tells me that while using possessive determiners can have a positive effect on conversion, the first person singular “My” can backfire.

In tests I’ve run, the second person “Your” has consistently outperformed “My”. My hypothesis is that the first person perspective confuses users and produces friction, as the rest of the communication on a website is usually in the second person form.

Secondly, from customer analyses we’ve learned that potential customers most often signup to WriteWork.com when they are in a hurry to get started on their writing process. Previous tests, I’ve conducted on WriteWork.com, have confirmed that adding a bit of urgency to the CTAs increased CTR.

Based on the points above, I created Treatment A:

 I reduced friction by removing “My” and increased perceived value and urgency by adding “Get Started”.

The test:

I ran the test for 10 days and concluded it at a statistical confidence level of 98%. Treatment A generated a lift of 31.03% in sales. I can’t disclose the full details on the sample size, but I can tell you that we had 100+ conversions.

The test described here is particularly interesting because – while the other CTAs simply move potential customers down the path to conversion – clicking this CTA actually means money straight in the bank. So, in this case, the ROI and return on time spent testing is through the roof!

Follow-up experiment – bigger isn’t always bigger:

The keen observer would have noticed that the copy tweaks aren’t the only value that has been changed. Adding the extra copy also increased the size of the button. So one might rightly hypothesize that the increase in size also had an effect on conversions going up.

In order to find out what effect the button size had, I ran a follow-up experiment with Treatment B where I increased button size but used the control copy in both variants.

I was quite surprised to find that Treatment B actually had a negative effect on conversions and reduced sales by 10.56%.

So the conclusion here is clearly that it was the copy – not the size of the button – that generated the 31.03% lift in sales.

Main takeaways:

First off, your CTA copy has significant impact on conversions. In this case a 31.03% lift in sales – not just CTR. If you want to get a quick lift with with a high ROI, optimizing your CTA copy is the ultimate low-hanging fruit.

Generally, the more relevance and value your CTA copy conveys, the more conversions you’ll get. In this case, adding urgency contributed to the perceived value of clicking the button (that doesn’t mean that urgent copy is always good).

The first person possessive determiner “My” can increase friction. In my experience, it’s better to adress your potential customers with “Your” or completely leave it out, as was the case with Treatment A.

And, as always, one of the main points I try to stress with case studies is the importance of testing. The fact is that testing really is the only way to find out whether your optimization attempts actually work.


  1. Great article. We have found very similar results. It always amazes us the looks on a client’s face when we share the metrics from A/B testing, especially the button size.

    • Michael Aagaard says:

      Thanks Marc – I’m glad you liked the case study!

      Right on! One of life’s small pleasures truly is the reaction of a client when you show them a minor tweak that generated a major lift ;-)

      Thanks for reading and please stop by again soon!

      – Michael

  2. Nice!
    My elaborate theory from the last post was wrong, but I ain’t mad. :)

    I love that you also tested the button size. That’s a detail I might have missed, myself.

    • Michael Aagaard says:

      Ha ha – yeah, that’s the thing with elaborate theories. Sometimes they become too elaborate ;-)

      Thanks, I was very interested in isolating the effect of the copy here, and I actually thought that the size of the button had a positive effect.
      Boy was I wrong. I love it when tests give you those “Wow I really didn’t expect that” experiences.

      – Michael

  3. Any thoughts on why the increased button size with the same CTA decreased sales? I would have expected a marginal drop or increase, but 10% is quite significant. Would have been good to reduce the font size in order to test the improved CTA in the smaller button size to see what happened.

    • Michael Aagaard says:

      Hi Tony – Thanks for your comment and great observations.

      You have a good point, I’ll set up a follow-up experiment with reduced font to see what the results are.

      I think the drop has to do with the fact that the copy is more important than the size of the button. Also, as you hint at, it might have something to do with the fact that the button looks weird when the copy isn’t adjusted in size.

      – Michael

  4. Thanks Michael! Very helpful :)

    Interesting the Follow-up experiment: “bigger isn’t always bigger”, sometimes people increse the CTA’s size just to try to grow the CRO but they don’t check/test the COPY!! Nice tip!

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