One of the smarter pieces of commentary I heard on this fall came in a podcast (Slate Money). The contributor pointed out that if you say you're going to do something - say, get 500k new subscribers this quarter - then that gets priced into the valuation. If you miss on those numbers, then the valuation is slightly out of whack, and you see a decline.
As ever with these things, you have to look over the longer term rather than make snap judgements from a single day.
Truth be told, I have no idea if Netflix's model can work in the long run. It seems to me that while they've ramped up production to cover all those shows that they'll be losing in the next 6-24 months. But I can't see that they can ever stop. They can hardly sit back and say, "Well we've made a dozen Adam Sandler movies now. Why don't you just keep watching those on rotation?" Scarily, they're going to have to make a dozen more (I admit it. I watched Murder Mystery. Truly "below average." Some great actors in there absolutely coasting along.)
And while international can take the weight off US numbers, that isn't necessarily a panacea. Tastes vary massively around the world. Unsurprisingly, people like locally and culturally relevant TV. Want to be big in India? You have to make Indian dramas. Want to be big in Brazil? You need local stuff. Want to be big in Turkey...? You get the picture.
Adam