[bhrgunatha]

> So if a user came to Hulu.com from an ad on Facebook, and then later, using a different browser on the same computer, visited Hulu.com from Google, and then at some point signed up for the premium service, KISSmetrics would be able to tell Hulu all about that user’s path to purchase (without knowing who that person was).

It seems their method relies on using cached javascript files to identify a user. How then are they able to track the same user using a different browser? Is it by IP address?

[inportb]

What happens when you login using both browsers? Now, Hulu.com can attribute both Km UID's to your account. Magic.

[robtoo]

How then are they able to track the same user using a different browser?

Flash cookies. Presumably Silverlight has an equivalent.

(And I even heard once that Windows Media Player shares cookies with IE regardless of the browser that it is embedded in.)

[zerd]

They can use browser fingerprinting, for instance. http://panopticlick.eff.org/