Hacker News Reader

You assume that everybody stores the visitor data in the cookie. Nowadays only the visitor ids are stored there, identification is made also by all the info you and your browser provides and the rest of the data which actually contains the user's interests and visited sites is in distributed NoSQL/SQL replicated databases.

I work in the ad industry, specifically real time bidding and I am thinking it would be kind of pointless.

View on HN

While browser/device fingerprinting has made great strides, if this was really pointless, you wouldn't see so much of hue and cry over some mozillas decisions to block third party cookies. (http://www.iab.net/mozilla).

Flashcookie and localstorage based techniques are hardly legal. Store user profiles server side, but you will still be fooled by a different visitor id in the cookie (and fingerprint for that matter), won't you?

Yup. So many work arounds. Simply the IP+UA alone contains enough entropy to uniquely detect the majority of users already, you don't need to store anything at all.

ETag cookies work quite well too and don't require any additional software or "hacking"-esque approaches.

Reply on news.ycombinator.com