In this article we'll zoom in on the metric Assisted Conversions from Google Analytics, and why we treat it as a non-aggregatable metric in Funnel.
What does the Assisted Conversions metric represent?
The image below describes a scenario where a user makes a conversion after having made three other recent visits to the website.
The three visits leading up to the conversion can be viewed as touch points that have been involved in assisting the conversion. In Google Analytics this relationship is captured by the Assisted Conversions metric, which is defined as:
"The number of conversions for which this channel appeared on the conversion path, but was not the final conversion interaction"
Why is this metric non-aggregatable?
If you consider the definition above it says the metric represents the number of assisted conversions for a channel. What channel means in this context depends entirely on the query you are giving to Google. In Funnel, the query is defined by the set of dimensions you include in your Funnel data source, but the same principle applies when working with reports within Google Analytic's own user interface. Please take a look at the examples below to get a more practical sense of how this metric doesn't aggregate nicely.
Let's assume you have a Google Analytics data source connected in Funnel where both the Source and Medium dimensions are included. If we consider the scenario in the beginning of this article, the data we receive from Google Analytics for this data source would look something like this:
Here, a channel means the combination of a source and medium value. With this data we'll be able to answer the question "How many conversions has each source and medium combination been involved in assisting?".
Now, let's say we want to answer the question "How many conversions has each source been involved in assisting?" instead.
If we were to simply remove the Medium column from the table above the resulting table would look like this:
If you think about the definition above and what this metric is meant to represent, this is not correct. The channel facebook has only appeared on the conversion path for one single conversion.
By setting up a second Funnel data source configured to query Google Analytics only with the Source dimension we would get the correct data set:
The behavior described above is the reason why we treat the Assisted Conversions metric as non-aggregatable in Funnel. This means that if you want to analyze Assisted Conversions from different perspectives (sets of dimensions), you need to set up multiple data sources in Funnel.