However, while trawling through Google's privacy policies, I found a gold-mine of opt-outingness, and it appears I was wrong. Not only can you opt-out of Google's and DoubleClick's profiling, you can opt-out of almost every other one! What this does it set a specific opt-out cookie, that will prevent the code running on the ad platforms from using or recording profile data to serve you ads. You will still see ads (unless you run Ad Block Plus), but they will not be based on inferences from your surfing history. As it uses cookies, this will only work as long as the cookie is there, so other browsers/computers won't have it, nor will they remain if you delete your cookies. I still recommend not accepting the cookies in the first place (Cookie Safe helps with that and is easier than managing it through browser prefs), but if you must (e.g. to use gmail) then there's very little reason to not opt-out.

While this is quite cool, and certainly makes me heap less derision on online advertisers, there is a caveat that you are trusting the advertiser that they have opted you out. For example, doubleclick.com still has an ASP session cookie set which could be used for profiling if they felt like it (several of the other ad partners also have opt-out cookies with what looks like unique identifiers present). I would still recommend blocking these third party cookies just to be safe, and you don't really loose anything by doing so. Additionlly, non-ad profiling such as your Google life-time (now 2 years) cookie or YouTube tracking cookie will still be present and used to profile you (unless someone can show me a cool way to opt-out of that?) so this certainly isn't a panacea.

The big problem is that anyone who indiscriminantly accepts third party cookies, is also not likely to know about/care about/find the opt-out page. Either-way, the Network Advertising Affiliates deserve some credit for this.