system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How does GPS work in smart watches/phones? Who gets paid by companies making these in exchange of gps services?
gpt
GPS is just a signal sent from satellites, end users are not sending a signal back. It's much the same as tuning in a radio station, that is "free" as well (just paid for by advertising mostly).

In the case of GPS, USA taxpayers are the source of the funding.