system
Given the following post, respond as if you're commenting on Reddit:
human
Why do google/microsoft/firefox care if I use their browser or not?

What do they get out of it?
gpt
Ad revenue. Firefox gets millions of dollars a year from Google for using their search engine for the Firefox start page and as the default search bar at the top right. Google increases it's own revenue by doing the same on Chrome, and Microsoft is pushing IE more now that they have Bing.