It's pretty funny how far Google will go to avoid talking about the weather. They even put barometers in all their phones but aren't building a weather network or buying any weather startups (like mine)! What gives? They algorithmically remove weather, create an unused network of 50,000,000 barometers, gah!
Perhaps because Google Weather[1] will actually control the weather. A Google Pumping station every half kilometer or so, they are going to use the barometers in Android phones to give feedback on their actions. So if you need sunny weather the pumping stations will pull air from outside the area in and heat it up, if you want it to rain they will create a low pressure zone by pumping air out to a different zone. They need all the barometers to control which pumping stations are on and how much air they pump.
[1] This is entirely fictitious of course, but having worked there I could easily imagine just this description on the 'ideas' page.
cheap barometers are pretty terrible for absolute readings, I am not sure you could get any useful (for weather observation) data from them in a reasonable way that would be better than from classic stations.
