mportant things you should know:
Opting out of the DoubleClick cookie means that Google’s AdSense partners, DoubleClick, and certain Google services using the DoubleClick cookie will know you have opted out of the cookie and will not attempt to assign other DoubleClick cookies in the future. You will see the same number of ads as before, but they may not be as relevant when you opt out.
Please note that if you use more than one type of browser or more than one computer to surf the Internet, you will have to opt out in each browser and on each computer that you use.
If you delete this opt-out cookie, you will have to opt out again. Alternatively, Google offers options for you to permanently save your opt-out settings in your browser.
You can opt out of other network advertising and third party ad servers’ cookies from the Network Advertising Initiative opt-out page.
If you are using a brand new computer or otherwise do not already have a DoubleClick cookie, it is possible that you will have a DoubleClick “test” cookie in addition to your opt-out DoubleClick cookie. The “test” cookie, which is used only to verify if your browser is accepting cookies, will self-delete within 24 hours. Once you have opted out of the DoubleClick cookie and the “test” cookie has expired, no other “test” cookie or DoubleClick cookie will be set again.
You can opt in again by visiting the Ads Settings and clicking the "Opt in" button.