I don't think they have a reason to care if people watch the show, per se. They don't get paid on a per-view basis, but by attracting new subscribers/forestalling cancellations, and that's something they can see a difference in right away.
The ideal series for them might be a show that nobody watches - but makes everyone think "I wanna watch that!" and either makes them subscribe or stops them from cancelling. (Realistically, if they never watch the show, at some point they will forget it exists, and then it will have no further value as glue to keep them subscribing.)
Hmm, they can see whether we add the show to our Instant Queue. So that counts, because it shows that we value it. Add the show to your queue and don't stress about when you watch it. They probably know the relationship between your queue length and the likelihood you will cancel your subscription. A queue with a lot of stuff in it is less likely to be abandoned. They should also be able to tell which shows are "sticky" just by sitting in your queue, unwatched, and how long the effect lasts. Damn, they must know a lot about us, now I feel paranoid!