Originally Posted by rowan

Here's some ways Google collects information about your sites and/or your personal (or business) habits

- google analytics
- adsense
- adwords
- gmail
- google search, with a long-held tracking cookie that gets presented for every search (and even if you delete it they could probably make a reasonable assumption that the search is still coming from you, or your computer)
- if you have PR enabled, google toolbar phones home for every URL your browser loads
- google answers
- google maps
- google books
- google calendar
- google finance
- google groups
- google pages (a bit like geocities for dummies)
- picasa
- youtube
- blogspot
- blogger
- google web accelerator (hey, send every single web object your browser fetches through us... it will be faster! we won't look! promise!)

Even small amounts of data can help - through data matching - with the bigger picture.