In CBS Test, Mobile Ads Find Users – New York Times Pssst, hey you! There’s a cheap latte waiting at the coffee shop on the corner! CBS plans to announce on Wednesday that it is trying one of the first serious experiments with cellphone advertising that is customized for a person’s location. Its CBS Mobile unit is teaming up with the social networking service Loopt, which allows its subscribers to track participating friends and family on their mobile phones. The ads will appear on two Web sites that are tailored for mobile devices, CBS Mobile News and CBS Mobile Sports.