That's true if you're the conspiratorial type - from a realistic/business point of view there are multiple customers. There are the customers that provide money: the people wanting to sell ads, and the customers that provide screen space: the ones that view the ads. If Google doesn't appease both, their business would fail. In some cases, it's in Google's best interest for people to have free/cheap access to web-capable devices. The easier it is for people to get on the web, the more people that will give Google screen space, and the more companies will give Google money to fill that space.