Aggregation: weighted average
It would be useful to have weighted average as one of the aggregation options for metrics. So for instance when we bring in advertising data, we could bring a calculated value for CTR and specify that when aggregating rows, GDS should take an average weighted by the impressions metric. Or for cost per click we could have an weighted average by clicks.
At Supermetrics, we are designing Google Sheets templates for bringing in ads data from sources like Facebook and Bing, but from a user point of view, setting these up is not very convenient as they now need to create the formulas for all the calculated metrics when creating the Google Sheets data source in GDS. It would be better if we could have the calculation done already in the Google Sheets side, and then the user could simply specify the aggregation to weighted average.