Cannot speak for all the teams in Windows, but my team has used it successfully to improve the battery life of machines through A/B tests.

We're able to (on insiders builds) try out postponing various operations until the machine is plugged in to see how it effects the user experience and power draw. It helped us tune a few operations in ways I wouldn't have anticipated to improve battery life without degrading the experience

One of the other comments mentioned this but the blog will also highlight some of the more user visible tests that are run. Generally around optimizing UI flows for usability

Do you have a link to the tests or the data?

I work on the indexer and am always looking for more data about what we are doing wrong.

Check out the top comment of this article: http://www.forbes.com/sites/jasonevangelho/2015/01/26/dell-x...

A commenter pointed out to the author that Windows Indexing was responsible for significant battery drain and the author confirmed by running the test again with it disabled.

Thanks, not great to see, but good to know what we have to fix

>Does this happen Windows Phone devices as well?

If they put the database in their isolated storage then no. Apps are sandboxed to their own isolated storage folder and cannot get access to the other apps folder (the source of your pain)

Edit: Spelling is hard