Two weeks after Nielsen announced that it will measure Netflix viewership, the company is out with some interesting numbers about just who is watching Stranger Things 2 on their TV sets.

It said a “significant viewing event occurred” when the buzzy creepshow returned October 27 for its second installment. Within the first three days, Episode 1 averaged an eye-popping 15.8 million U.S. viewers and nearly 11 million in the demo viewing on the TV. Nielsen also said all of the nine new episodes averaged 4 million viewers and 3 million in the demo.

The binge-watching crowd also was out in force to see Mike, Dustin, Lucas, Eleven and the rest battle the forces of the Upside Down: Nielsen says 361,000 people watched all nine episodes on the first day.

Nielsen said last month that its new SVOD metrics would include not just ratings but data points such as reach, frequency and segmentation reporting — elements common for years in the world of linear TV. It launched with streaming leader Netflix and expects to expand to Amazon Prime and Hulu.

Nielsen, however, is tracking on TV viewing, not on mobile devices.