Last week, Netflix announced that Season 3 of Stranger Things was the series' most-watched season to date after being viewed by 64 million households in its first four weeks on the streaming service. But how does the platform figure out what counts as a view?

Since Netflix doesn't adhere to the traditional Nielsen ratings approach for broadcast and network television, we're left taking the streaming service at their word, even when their numbers seem too astronomical to be true.

In a letter sent to a UK parliament committee, Netflix provided some insight into how the streaming service determines viewership, which is then used to decide if a series should be renewed. The Verge reports that Netflix breaks down their ratings into three categories: "starters," "watchers," and "completers."

"Starters" are determined by the "households that watch two minutes of a film or one episode" in a series while "completers" are considered "households that watch 90 percent of a film or season of a series." Those two specific categories, which account for the first seven days of a release, and the first 28 days thereafter, are shared with producers and directors.

Meanwhile, "watchers" are the "households that watch 70 percent of a movie or one episode in a series," and it's the category that Netflix uses in quarterly earnings letters and shares with the public when the news involves one of their show's record-breaking performances, like the aforementioned announcement regarding Stranger Things Season 3.

Netflix's letter to the UK parliament committee stresses a desire to be more transparent over their numbers. "Depending on how useful our partners find this data, we will consider sharing it in more countries outside Europe and North America," the letter says.

The letter's talk of more transparency aligns with the mindset of chief content officer Ted Sarandos who promised to be more forward with their numbers this year. "I think it’s important for artists to understand, to have the audience also understand the size of the reach of their work," Sarandos said. "So that’s why you’ll see us ramping up a little bit more and more and giving out — sharing a little more of that information."