The real question is, why is their PR so good for a company of this size?
It's not PR. They rest their laurels on the PR their users afford them for their products. They have an extremely loyal following. Heck, even a smilie on this site: :google:.
The company is sick with hubris and arrogance from the inside. And I fear how their massive culture of entitlement will weather the inevitable first unprofitable streak that happens to every business (when they take a brief fall, I can't see it being anything short of hard).
But Google scores massively on what's called "
Net Promoter Score" (or NPS, developed by some marketing consulting geeks at Satmetrix). As a measure of user loyalty, it's not really about how often a user visits, etc. Perhaps a truer measure of user loyalty is how much a user/customer is willing to stake their own reputation on the line by making a recommendation of them to a trusted friend.
The NPS for a company is essentially taking the percentage of users who rate among the highest recommendation promoters and subtracting the "detractors" -- or the percentage of users who wouldn't recommend them to a friend.
In the airline industry, for example, they found no airline was capable of increasing their profits without also improving their NPS.
So Google's success isn't about what a PR team is saying about them. It's about what Google users are saying about them to their friends. Some merited, IMO, and some undeserved.