I'm sure they do for their own purposes already, you probably just aren't aware.
Thanks, it might be a good idea, but unless they've said they do this, I won't assume it.
They are in the business of collecting data and selling it. I would assume they do.
That said, it's really only for their channel. They can't really collect that information and tell Netflix to try to target getting a show/movie. though, they might make those search results available to their top channel developers.