I don't know in Canada, but here in Japan, that button is as useful as a pack of kittens sitting on my desk. Let me elaborate on that:
Here in Japan, we do not have access to the Google Books store nor the Music store, rendering those 2 parts of the app effectively useless. I do have access to my android apps, which, as +Daniel Lemire
well said ,has no place in my desktop.
We also have access to a poor collection of videos that you can rent for 4 USD /72 hours. In a country where renting a video is as cheap as 1 USD/week and buying it costs about 5 USD it's just a bad market strategy. They not only had a terrible idea with this play thing, they are applying it terrible to other markets than US.