They have about 15%, and that's 15% of a huge market: every single person with an Internet access uses a web browser. That's about 3 billion people last time I

They have about 15%, and that's 15% of a huge market: every single person with an Internet access uses a web browser. That's about 3 billion people last time I checked. 15% of 3 billion is still 450 million, which is a lot of users. In addition, a web browser is pretty easy to monetize because it's the entry point for the web. The default search engine has the lion share but there are other revenue streams (like non-default search engine, for ex. Amazon, the unfamous pocket button...) From the number you said, they're monetizing less than $1 per user per year, and actually I think it's a bit low. It may be due to them not monetizing on European users where they have a strong market share (about 22%).