“An idle Android device communicates with Google nearly 10 times more frequently as an Apple device communicates with Apple servers. These results highlighted the fact that Android and Chrome platforms are critical vehicles for Google’s data collection.  Again, these experiments were done on stationary phones with no user interactions. If you actually use your phone the information collection increases with Google”.
“In fact, location information constituted 35 percent of all the data samples sent to Google”.

Source : Google Data Collection research – Digital Content Next