We are using different kind of advertisement (like Google adsense) to display ads on our site, these ads are used to earn revenue for site.
Google’s use of the DART cookie enables it and its partners to serve ads to your users based on their visit to your sites and/or other sites on the Internet.
The DoubleClick DART cookie is used by Google in the ads served on the websites of its partners, such as websites displaying AdSense ads or participating in Google certified ad networks. When users visit a partner’s website and either view or click on an ad, a cookie may be dropped on that end user’s browser. The data gathered from these cookies will be used to help better serve and manage ads on the publisher’s site(s) and across the web.