El Toro - The Postman of the Internet
ElToro.com is a digital marketing solution that has mapped over 160 million IP addresses to the physical household address. By doing so, ElToro.com can surface digital display ads on the computers in those homes when a person there is browsing the Web. Simply put, ElToro.com is the postman of the Internet. You provide ElToro.com a list of physical mailing addresses and instead of the home receiving a post card, they receive digital banner ads.
Via: http://eltoro.com/el-toro-the-postman-of-the-internet/