The Ultimate A/B Testing Guide Part 3: The Most Common Mistakes

The Ultimate A/B Testing Guide Part 3: The Most Common Mistakes

A/B testing is a common marketing strategy that allows businesses to measure the effectiveness of their campaigns. A/B tests compare different versions of a website, email, etc., to see what’s more successful. While the theory behind this seems straightforward, be aware of some key mistakes that marketers often make when conducting A/B tests.

Mistake #1: Testing only one version at a time

A/B split testing is a way to determine which design causes more conversions. However, when A/B testing only one version of a design, you are missing out on the data from the other design.

You have a hypothesis that people will prefer your original product to the new product you are testing. So you decide to only test ONE version at a time. This means that you are not getting the full picture of what your visitor’s likes and dislikes are.

Mistake #2: Testing too many elements at once

There are many companies that use A/B split testing to tweak their marketing process. Yet, most companies do not know what they are testing until they get to the stage of actually launching the test. This can lead to a lack of data gathering and ultimately, poor results.

Over-testing the page can lead to confusion and false results. In order to avoid this, it is important to have a clear idea of what you’re testing before implementing it.

Mistake #3: Using unbalanced traffic

Companies should make sure they evenly distribute their traffic throughout their trial runs. If you’re not careful, you might find that the percentage of traffic from a certain version is too high and the other is too low. This can lead to skewed results. Making it difficult for you to determine which version will be most successful in the long run.

When a website is busiest on Mondays, it would be a mistake to run an A/B test on Monday since the traffic will not be representative of the website’s typical traffic. The best time to run an A/B test is when you have the least amount of traffic on your website. This allows you to see how your content performs with minimal interference from other factors.

Mistake #4: Running an A/B test too soon

Some companies run an A/B test too soon because they are eager to see the results. They want to know what changes will work for them and what will not work for them so they can act accordingly.

This mistake usually leads to unfavorable results. Running an A/B test on a low-traffic site is not recommended. Because it would be difficult for the experiment to reach statistical significance. And the data collected cannot be extrapolated into general conclusions.

Mistake #5: Not running enough tests

In order to improve the effectiveness of your website, you should run a series of A/B tests to see which design works better. If you’re only running one test, then you’re not going to get a complete picture of the site’s performance.

One of the most common A/B test mistakes is not running enough tests. That can result in missed opportunities for optimization and improvement.

Mistake #6: Not understanding the data collected from the test

The mistake that marketers make most often is not analyzing the results thoroughly enough and making changes based on false assumptions.

Not understanding the data collected from the test can make it difficult to determine what’s working and what’s not. When you don’t analyze the results in detail, you might be missing out on huge opportunities to improve your business’s revenues.

Mistake #7: Not planning your optimization roadmap

To make sure that the A/B test is successful, it’s important that you have an idea of where the experiment will go down. The first step is to come up with an A/B test plan and make sure that it includes all the necessary steps. Without a proper planning process, copywriters can make costly mistakes in designing and implementing their campaigns.

Mistake #8: Ignoring statistical significance

Most people determine whether or not an update has been successful based on their intuition. Gutfeeling is an important part of decision-making, but it is not a sound base for making big decisions. Unfortunately, when companies perform A/B test, they often fail to consider the statistical significance of their findings.

Mistake #9: Testing for incorrect duration

One mistake marketers often make when A/B testing is that they test on too short of a time frame and then fail to see any results. This can lead them to think their strategy is ineffective when it actually works just fine on a longer timeline.

On the other hand, the mistake of testing for too long can lead to diminishing returns. Because the results will not be as significant as they would have been if they had tested for shorter periods of time. If they are not careful, they might end up wasting time on the wrong version and ultimately not getting any results.

Mistake #10: Failing to follow an iterative process

It is important to understand that A/B testing is an iterative process. It should not be done in a single step. But rather on a regular basis and the results of the test should be analyzed to see if it was successful or not.

The iterative process involves conducting a test, analyzing the results, and making changes based on what was learned. This process allows companies to continuously improve their product without wasting time or resources.

Mistake #11: Failing to consider external factors

External factors are those things that are not related to your website or landing page content but affect your audience’s response in some way. When conducting an A/B test, you need to consider multiple factors. Such as your target audience, the time of day, the number of users logged in at the same time and more.

If you don’t take into account all the external factors, it can lead to underperforming results and wasted time and money.

Mistake #12: Using the wrong tools

One mistake is to use a tool that doesn’t provide enough data for the business to make an informed decision about what changes should be made. Or a tool that does not offer an easy way to track conversions or revenue generation.

There are many tools available for A/B testing on websites and apps including Optimizely, Google Optimize, and Unbounce. It’s important to choose a tool that has metrics related to your business needs so you can make smart decisions about how to conduct your tests.

Mistake #13: Sticking to the plain old A/B testing method

A/B testing is an effective marketing tool, but it can also be very misleading. It’s important to know when to stop using A/B testing and use multivariate testing instead. The most common mistake marketers make with A/B tests is sticking with the same test design over and over again. Without taking into account the data that they have gathered in the past.

When you do so, you are not able to see how your audience responds or what type of content works better for your website.


A/B testing has been around for over 50 years and is still one of the most effective ways to test and improve your website. The key to success with A/B testing is understanding how it works, being able to make decisions based on data, and having patience when results come in.

A/B split testing was once an exclusive method of marketing. However, with the increasing popularity of big data and predictive analytics, marketers are turning their attention away from this costly trial-and-error method and instead opting for more sophisticated methods.

Leave a Comment

Your email address will not be published. Required fields are marked *