I must say that everything that is customizable in Google Analytics gives you great benefits and pleasure. Custom dimensions, which are called special dimensions, are also gives you benefits. Custom dimensions are not different from existing dimensions in Google Analytics. The only difference is that you create it according to your own setup.
It will be more comfortable to explain with samples.
Let’s say you have an ecommerce site and you want to analyze the payment methods used for purchases made from this site. If you want to know which bank customers do more shopping, which payment systems do customers use more,which payment system users add more product to their basket the custom dimensions make your business very easy.
How to install Custom Dimensions
It’s fairly simple to set up custom dimensions through Google Tag Manager. Suppose you want to receive payment method information. You can send the paymentMethod variable to the dataLayer that you are running for e-commerce tracking on the thanks page where the shopping ends. You can also add this variable as a new GTM variable through Google Tag Manager. By doing this, you’ll have the chance to send the variable you see in dataLayer to any medium you want (Google Analytics) via GTM.
After you have done the above, you must create a new custom dimension by coming to Google Analytics. When creating this custom dimension, you are prompted to choose a hit, session, user, or product. We need to choose the current example as a session because the custom dimension we have prepared will be a custom dimension resulting from a session.
Once you’ve created the custom dimension through Analytics, we go to Tag Manager, and we come into the Custom Dimensions tab by entering into the tag that we triggered in terms of page display on Google Analytics. In this tab, we send the number as index when we see setting it in Analytics; and the payment Method variable as “Dimension Value”, which we created on GTM.
After we make sure of our choices, we get it published and the data starts to flow into that dimension. Then we get an image like the screenshot below.