Misunderstood Metrics: Custom Dimensions

If you’ve made the leap into custom dimensions with Google Analytics, you’ve probably also tried to make a custom report to segment your traffic with the new dimension. You add the new dimension and suddenly the numbers don’t look right! What gives???

adding-a-custom-dimension-to-a-report

Like several other special dimensions in Google Analytics, the Custom Dimensions do not have a an empty ‘(not set)’ value. If you include the dimension in a report, there is no catch-all row to total up all the sessions that didn’t have a value to display. Instead, the report simply drops all that extra data.  Make sure you check the fine print (light grey text under the column aggregate numbers) where you’ll see a comparison to the website totals.

If you are building a custom report or dashboard, it will be important to keep this context when you start segmenting by your new dimension. e.g. Of the 24% of sessions that had a custom dimension value…

Keep Learning: Other Misunderstood Metrics