For this post, you've been awarded +3 Internets.mario said:
Google's main revenue is advertising, and by a landslide ( http://investor.google.com/financial/tables.html ) the percentage is bigger than Facebook's. Google's privacy has gotten so convoluted with their recent changes and Google+ integration that even Microsoft will run a campaign outlining Google's new privacy mess ( http://www.tomshardware.com/news/Microsoft-Ad-Google-Privacy-Policy-changes-track-information-advertisers,14610.html ).
Remember Google is an advertising company and their main source of income is selling your data to their clients, just like Facebook does.
Facebook's filing for their IPO actually shows that they are a very serious company with great profits and changes like their new Timeline feature show that they are not afraid of innovation. Their solid finances show no sign of being a bubble. And I'll even go as far as saying that in 5 year Facebook will be even a bigger player on the Internet and who know maybe they'll go into the hardware business with tablets and smartphones.
And if you are worried about privacy please opt-out of personal tracking here: http://www.google.com/ads/preferences/?hl=en and http://www.networkadvertising.org/managing/opt_out.asp
Personally I use Facebook's and Google's services, I'm just not sold on their "Don't be evil" motto anymore and neither should you.