system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 how non-advertising, free services make money. For example, WhatsApp doesn't advertise, is free and is worth millions of dollars.
gpt
When a service is free, you are the commodity being sold.  The app ultimately is in the analytics business, and the data on user habits could be valuable to third parties, for reasons as boring as selling you goods... and reasons as nefarious as keeping citizens on the straight and narrow (hopefully not).