Netflix's original shows feel like must-watch TV, but how many people are actually watching? The streaming giant won't divulge its viewership data, so it's fallen on Nielsen to plug the hole. Now, the audience-tracking firm is offering its first insights into what a hit Netflix show looks like -- and, the numbers are big. Fittingly, the initial set of Netflix ratings are for Stranger Things 2 -- the follow-up to the '80s throwback thriller that remains ingrained in the cultural zeitgeist. According to the results, the first episode of the second season was watched by 15.8 million people in the US within the first three days. Binge watchers also tuned in, with 326,000 people streaming all nine episodes on the first day.