system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: In TV Shows they showcase how many viewers it garnered, how are they able to collect this data?
gpt
In the olden days aka pre-streaming services this was mostly determined by a single company called Nielsen Media Research. Nielsen selects demographically representative families that they regularly survey to ask what they’re watching, and use math to extrapolate nationwide numbers. Same company does audience ratings, too. You may have heard “Nielsen ratings” before — same people.

Now with streaming services, networks can just directly measure viewers, but Nielsen still measures this for shows watched through traditional cable.