I look forward to hopefully knowing what you've discovered! It'll be an interesting study, I'm sure, and I'm intrigued as to how it goes. Best of luck with it!
Unfortunately, we cancelled our streaming subscription, so I can't actually see my streaming history. The only streaming title I recall watching in the last year was "God Grew Tired of Us". The other films either weren't available as streaming titles when we rented them, or we (my girlfriend manages the queue) weren't aware that they were available instant at the time of scheduling.
As you can see, the vast majority of the content we watch isn't available through a streaming subscription. If Netflix wants me to be a streaming customer, then they should work on getting this content available through their streaming service.