When reading the post related to Google's ad targeting policy
blogoscoped.com/archive/2007-0 ...

it appears that Microsoft _really_ has different plans when targeting advertisements.

Microsoft is planning to use "cameras, remote controls and biometric sensors to detect the identity of the person viewing a TV, cellphone, or computer monitor display. "

Link to the patent application:
appft1.uspto.gov/netacgi/nph-P ...

Source:
techdirt.com/articles/20070730 ...