Click through metric is available in SiteCatalyst, Discover, ReportBuilder and ExcelClient but not in DataWarehouse. Could you please make click through metric available in DataWarehouse as well.
The click-throughs metric is the same as Instances, which is already available in Data Warehouse. In SiteCatalyst and other tools, the Click-throughs metric is designed to be used in the Tracking Code and Campaigns reports, but nowhere else. In other reports, it becomes Instances. Since Data Warehouse allows you to combine multiple dimensions without respect to report-specific metrics, Instances will be the metric to represent click-throughs in DW.