Gmail

• What stores I shop at and how much I spend at each
• What credit cards I have/Which banks I use
• Who my friends are
• When I will not be home (from my flight confirmation emails)
• How much I spend on gifts and for whom
• Any social network acct I have and access to them
• Any web app I signed up

Google Calendar

• My social calendar : when I meet up with my friends, what we tend to do
• My work calendar : what my meetings are about (if I use outlook sync)
• My personal appointments (doctor visits, waxing, haircut, massage appointments)

Google Reader

• Blogs I read
• Blogs I pretend to read by subscribing but not actually reading
• Blogs I deem important enough to share with others
• My guilty pleasure blogs (blogs that I never share but read 100% of the posts)
• Content type I love
• Which friends’ shared items get my attention
• The fact that I am an occasional insomniac (from the hours I use GoogleReader)

Web History (Google.com)

• Basically every web search I made

Google Maps

• Knows my home address and my office address
• Any new place I look up directions for
• Any road trip I plan
• My commute hours from my live traffic searches

Google Profile

• Knows my real name
• Knows where I work
• Knows what I do for a living

There’s probably even more that I don’t realize. Isn’t it terrifying? What else does Google know about me? About you?