doubleclick.net is a domain used by Doubleclick which is an advertising company that is part of a network of sites, cookies, and other technologies used to track you, what you do and what you click on, as you go from site to site, surfing the Web. Over time, sites like doubleclick.net can help make an online profile of you usually including the sites you visit, your searches, purchases, and other behavior. Your profile can then be exchanged and sold between various companies like doubleclick.net as well as being sold to other advertisers and marketers.
More about Doubleclick:
DoubleClick is the ad management and ad serving technology foundation for the world's buyers, creators and sellers of digital media.