Google Analytics now has the ability to process custom item-specific parameters from ecommerce events that occur on your website or app. These parameters can be registered as custom dimensions and available for exploratory analysis.
what do they do Item-level custom parameters give you the opportunity to collect more data about products on your website or app than the standard parameters provided by default. For example, you can use item-specific custom parameters to get information about product color, size, customer ratings, and availability.
How to use. When establishing a custom dimension or metric, you must specify the name of the custom event parameter or custom user property that Analytics will link to the new dimension or metric. Analytics then populates the newly created dimension or metric with values collected from the respective event parameter or user property.
best practice. We recommend using the default dimensions and metrics before creating custom dimensions and metrics.
For advertisers with standard properties, don’t generate too many high cardinality custom dimensions. It can adversely affect reports and aggregate data under (other) rows.
Also, it is not considered a best practice to register custom dimensions for parameters that are already defined as dimensions, such as page/screen dimensions, transaction IDs, etc. This does not affect cardinality, but it does consume some of your custom dimension quota.
limit. If you hit the following limits, we recommend that you archive what you don’t use and create a new one.
Dig deeper. For information on how to archive or configure custom dimensions, see Analytics help guide.
why you care. Custom dimensions and metrics provide valuable insights that can improve your advertising campaign performance, improve targeting, and ultimately increase your return on investment (ROI).