[ghaff]

So?

The reasons the networks cared about the Nielsens so much was that they directly translated into how much they could charge for a 30 second ad block.

Netflix obviously does care about how many people are watching its shows. If no one is watching licensed content they won't renew licenses on it or similar content. If a new show isn't doing well and doesn't have passionate fans, they'll cancel it. (Possibly faster than a network would have.)

But they only care about how many people are watching something to the degree it increases the number of people subscribing which is a correlation that is harder to measure.