We build a webapp that allows users to run the app under their own subdomain. So we run the app under search.domainX.com, search.domainY.com and so on. They each have their own Google Analytics to track individual stats. But we want to know what general traffic for all clients of our app. So we want to know stuff like "among all our clients we had x number of views." What is the best way tool to track that sort of thing.