Its not common. Android is a Google device and the default search provider is Google on 98% of devices.
And to respond to the Ohio guy, Google makes money off Android from ads in free apps, paid apps, music store, tv/movies and etc. Not just the ads in Google search. And now since Google just announce Play Store gift cards, they have just open themselves up to a much larger potential to make money.
Also, remember when DSL first came out and the 56k users said, "There's no need for 1.5 mbps." Now 1.5 mbps is dialup by today's standards.