Out of curiosity, I stalked myself for 10 days using Mozilla's Lightbeam for their Firefox browser.
163 sites visited, 462 third party sites loaded in 10 days. I have disconnect plugin loaded into Firefox. It's stopped thousands of sites in the same time period.
Lightbeam makes a pretty graph of all these sites, how they are connected, and what unrelated sites also link to the same third party sites.
Again, it was curiosity. I wanted to learn the data generated about my normal browsing. Most of my browsing is tied to work. Some browsing is just looking through news sites to keep in touch with the local community. Some is from people who chat me links either they find interesting, or they think I'll find interesting.
I'm sort of surprised at the consistency of sites browsed over a random 10 day period. I'm surprised at how often the 3rd party sites appear. Here is my current list of extensions in Firefox:
Disconnect catches a lot of stuff, mostly the least desirable trackers. However, there are clearly a ton of third party sites included in many web pages.
In the end, I find it disturbing that I simply request 35% of the sites actually served to my browser. I asked for 163 sites, yet received 462. I'm not publishing the list of sites yet. If I did so, it would give a clear list of where I bank, where I volunteer, what I browse, what news I read daily, etc. Comically, the top 10 3rd party sites likely already know this. I wonder if I can buy my own traffic from the companies to see what they know about me.