title: How to determine demographics of users visiting your site?
body: <p>Ad-Servers seem (and do) know a lot about the use who is visiting a certain webpage leveraging Behavioral and Contextual Targeting.  I would love to be able to keep track of that data as well.  In particular I would like to know:</p>
  
  <ul>
  <li>age range</li>
  <li>male/female</li>
  <li>geographical info</li>
  </ul>
  
  <p>I would like this information on a per request basis (not a daily summary)</p>
  
  <p>What is the best way to accomplish this? </p>
  
  <p>Thanks!</p>