What are the drawbacks of using a single custom dimension and a single custom metric in GA to track everything?
Ok, I am limited to 20 custom dimensions and 20 custom metrics for a property in GA. But the number of values for a single dimension is unlimited.
So, I will be able to, for example, create a dimension called Dimensio and a metric called Metri. Then, if I want to track a custom event called Ev1 I will tag on Dimensio with value Ev1 and on Metri with value 1.
I am just suspicious, why having such a solution GA ever worried about having 20 dimensions and 20 metrics (it would be enough to have 1 dimension and 1 metric).
Thank you.
There are numerous reasons/use cases where you'd want more than 1 dimension. I'd suggest some reading on scope.
One use case that will break the 1 dimension usage:
For a music streaming service, you want to track the user type (premium vs free) and as well as the version of the app (v1.0.1 vs v1.0.2) for debugging purposes.
The user type should be on a user scope, as in it will persist as long as the user doesn't clear their cookies. The version might be on a hit scope, as you might push out an emergency fix part way through the user session.
Using the above use case, you cannot report on the user type as well as version in the same report if you were only using one dimension.