We are in the process of rolling out Insight and we have a fixed number of licenses. If we had the ability to easily report on Insight usage, it would make it much easier for us to manage Insight licenses.
Right now I'd settle for just knowing what people are connecting to the data set, on what dates, and how many times per day.
Stretch goal would be to know what dimensions they are using. (for use in trying to identify unused dimensions that could be removed)