system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do companies like Google and Microsoft spend so much money on, and care so much about you using, their web browers they give you for free?
gpt
You are not their customer. Their customers are the advertisers who spend money to get access to data about your browsing habits to serve you customized ads. For Google, getting people interested in Chrome is like  a mining company looking for more veins of gold.