As I couldnt believe the percentage of power wasted I had a read through the PDF and it turns out that all the apps were only run for less than 30 seconds. So you start up the free app it downloads advertisment at the start and before the app can run normally you close it and use this data for statistics. No wonder they get numbers from up to 30% used by ads.
Imagine car makers getting stats of a cars fuel consumption with a cold engine and only driving 5 minutes in a city stop and go. Before hitting the open road.
Microsoft doesnt seem to like the free app model Google prefers for advertising. Hard to compete with free...