That's some very generous speculation. I'll grant you that ads is quite obviously (based on our public filings) profitable, but that doesn't mean every venture seeks to insert ads.
I don't think it's speculation at this point. It used to be about who could control the family room TV experience. Now it's about who can control not only the family TV, but also the whole ecosystem of smart devices in the home that you will interact constantly with such as voice assistants and those tablet/hub things. It's all for ads, they're already doing it.
