Google passively makes money proportional to the number of people browsing the web. It is in Google's greatest interest for everybody to be online at all possi

Google passively makes money proportional to the number of people browsing the web. It is in Google's greatest interest for everybody to be online at all possible times and in all places. It doesn't matter where you are, what you are viewing. Your presence (in large numbers) converts to earnings for google, due to their large spread of Adsense ads. Gmail, for example, has been a highly profitable endeavor. Not because they can serve ads, but it raised the bar for browser based email. More people are doing email in their browser because Gmail came out, whether it's on yahoo, hotmail, etc. Not leaving the browser increases the time spent browsing the web, which increases pageviews on google ads. Android is just another free product Google uses to keep you browsing the web as much as possible.