Chrome Apps
Firefox was really the first Internet browser that offered serious customized through apps but Google’s Chrome has take they ball and run away. Chrome is one of the most modular browsers you’ll ever run into and works incredibly well on desktops and mobiles.
It’s not hard to see how producing their own web browser is a good deal for Google. In their view, anything that keeps the end-user engaged in the Google ecosystem, is a major victory so they don’t worry too much about giving it out for free.
Google’s got such a massive market share that pursuing free models like this is no problem at all.