Along the same line of thought, here's a new concept by MSN that tries to determine the probablity their "Commercial Intention and the confidence score":

http://adlab.msn.com/OCI/oci.aspx

This is why all your sites/pages should use different "formulas".

REMEMBER, you don't have to put a revenue stream (FINGERPRINT) on every site you do. You can use some sites/domains to steer traffic to your revenue sites.

When it comes to SEO, remember to always mix it up within your own networks.