I introduced the students in my class to Google Analytics. The purpose of this exercise was not to demonstrate how to properly "monetize" (oh, man, do I hate that word) a site, but rather to demonstrate the breadth of information harvested, even when we just visit a site.
For me, being a datahead, I like to think in terms of read-only (RO) and read-write (RW) when it comes to information. In his book Remix, Lawrence Lessig speaks about RO culture vs. RW culture. He uses it to juxtapose the old paradigm of cultural consumption (listening to music, watching movies, reading text) - RO - with the modern process of collaboratively creating culture by using technology to create music, videos, and text that build upon other works (remixes) - RW. I know that this is technically inaccurate, but I often think of the old Web, Web 1.0, as being RO. Sure, anyone could post to it with a text editor (or Netscape Communicator) and an FTP client, but you had to know some HTML have have access to an animated GIF of a guy digging. :) That is, content was created by a small, select group of nerds. I think of the modern, Web 2.0 culture of being RW - it's trivial to write information to the web by filling out a form (blogs, comments, Facebook), no knowledge of the workings of HTML required. Therefore, it's more open, more egalitarian; anyone can contribute without having to be a tech guru.
That said, we often think of posting information to web to come from RW activities - updating Facebook/Twitter, posting to a blog, tagging a picture, etc. So, I find it both interesting and a little scary the amount of information we "post" to a site just by engaging in an RO activity, browsing web pages, classic Web 0.1. In a standard session of browsing the Web, you leave this information on every site that you visit, possibly more information than you intentionally post to your Facebook site - your current location, the terms you search for, etc. At least on Facebook, you consciously choose which information to post.
So, I guess the moral of the story is that everything you do on the web is RW. We constantly leave a breadcrumb trail as we visit sites, usually without knowing we're doing so. I'll show you how to leave less of a trail tomorrow.
Until then, I'm off to check my Analytics to see how you got to my site...