John Graham-Cumming: What’s wrong with Flash Cookies?
: Macromedia created a “parallel” cookie infrastructure, which is not cleared/controlled by browser cookie controls. Heinous! I had no idea. Checking mine, it was full of ad-tracking crap
(tags: cookies flash privacy crapware ads)
You can also be tracked by http cache identifiers like etags. Advertisement retargeting is a huge business and lives on this data. I have also heard the ip+useragent is commonly used to uniquely identify users.
Etags! That had never occurred to me.
I’ve learned a lot about advertising since joining an display advertising company last year –
There’s luck with the sane advertisers out there, though. NAI lets you opt out of a boatload of advertiser tracking:
The ‘opt out’ is much much better than simply deleting your cookies.
Excellent! Thanks for the tip, I’ve link-blogged it.