Amazon Link: http://www.amazon.com/In-The-Plex-Google-Thinks/dp/145587572...
She told the interviewer (I believe Steven Levy) that they train future managers by sending them all around the world and spending a ridiculous amount on each one, but they only expect one of every five or six to be there within three years. They want those type of people because they are ambitious and they want the Google ideology everywhere so they are happy to do it. Essentially, even if you can only get an employee for a year, Google usually highers the best and brightest so they'll probably achieve great things AND when they move on there will still be a connection to Google (and spread Google ideology).
Also, from the ex-Google employees I have talked to they don't feel they can make a big enough difference and would rather join a startup. That's probably because they vet the applicants so well to get ambitious individuals they end up losing them because they want to start or join a new company to both make more money and make a larger impact.
Additionally Google did try to disrupt the cellular companies a little by selling their phones unlocked through their own webstore, but the American market didn't buy them. Yes there really is only one network that gave you a deal if you did this (T-Mobile), but Americans seem to prefer subsidized phones with absurd monthly plans rather than paying for the phone up front and being free to choose the network.
It is a fascinating book and one that I regret not reading earlier.
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