The Optimization tab
Running an experiment allows you to compare one of your ad settings against a variation of that setting to see which performs better. Experiments work by splitting your site’s traffic between the original ad setting and the variation, so that their performance can be measured side by side. Experiments help you to make informed decisions about how to configure your ad settings, and can help you to increase your earnings.
Here are some examples of the types of experiments that you can run:
- Compare the performance of text-only ad units to ad units that have both text and display enabled
- Analyze the effect of changing the color of ad text on ad performance
- Determine the impact on your revenue of using ad serving, sensitive and/or general category blocks.
There are two ways to create experiments. You can either:
- Design your own experiment - you set up the experiment yourself by choosing the ad setting and creating the variation.
- Run an experiment from an opportunity on your Optimization tab - we set up the experiment for you based on the settings change described in the opportunity.
Life of a typical experiment
A typical experiment that you design yourself, follows these steps:
- 1. Preparing for your experiment
- 2. Creating your experiment
- 3. Monitoring your experiment
- 4. Choosing the winner of your experiment
Before you create your experiment it’s a good idea to decide exactly what you’d like to test in the experiment.
Ad unit settings: All ad type and text ad style settings are available for experiments. If there are multiple changes that you would like to try (e.g., change the text ad background color and increase the text font size), you may want to run two different experiments - first an experiment for the background color change and then an experiment for the font size change.
Note that the following ad units are not eligible for use in experiments:
- Idle ad units
- Ad units that are already being used in another experiment
- Matched content units
Allow & block ads: The following ad blocking settings are available for experiments:
Note that there are some limitations on the number of experiments that you can have running at any one time:
- You can only run one ad unit settings experiment per ad unit.
- You can only run one "Allow & block ads" experiment at a time.
- You may run both types of experiment at the same time.
When you create an experiment you:
- Select the original ad setting that you want to compare the experiment variation against.
- Select which settings you’d like to change for the variation.
- Choose whether you'd like Google to automatically apply the winning setting for you after your experiment has finished.
Selecting this option can help save you time, for example, if you're planning to run lots of experiments.
The “create experiment” page guides you through each step, and provides you with more information. When you’re finished setting up your experiment, you can start it.
Once your experiment is up and running, it’s up to you to monitor its progress.
After a few days, you should start to see data in your experiments list.
Over time, you should see either the original ad setting or the variation outperform the other. To help you decide the right time to choose your winner, we calculate a confidence score for the two settings. This score indicates how likely the original or the variation is to be the better performing (e.g., the highest earning) setting.
We recommend that you wait until one of the scores reaches at least 95% before you choose that setting as the winner. When a setting has a 95% confidence score it means that we are 95% certain that that setting is the better performing of the two.
- If you choose the original as the winner, then your original settings are retained.
- If you choose the variation as the winner, then we apply the settings of the variation to your account.
In either case, we stop splitting your traffic, and your experiment ends.
- If you've opted to let Google choose the winner of your experiment, the best performing settings will be automatically applied for you.
- You can stop an experiment at any time without choosing a winner. If you choose to do so, we’ll revert your settings back to the way they were before you started the experiment.
Automatic experiments are experiments that Google runs on your behalf. By allowing Google to experiment with a small percentage of your traffic, you get better and more customized opportunities to help improve your account performance. Opportunities from automatic experiments come with a "verified by experiment" label which means that you can be confident in applying their recommended changes right away.
To switch on automatic experiments:
- Sign in to your AdSense account.
- Visit the Optimization tab.
- Select Experiments in the left navigation.
- On the "Experiments" page, switch on automatic experiments.
If you have further questions about experiments, see the Experiments FAQ.