Orange Spain is to cut mobile customers' bills if they agree to the ringback tone, heard by anyone calling them, being replaced by adverts. The dial-tone promotions (Promo Tonos) uses a tool developed by Corporacion Multimedia to help advertisers and media agencies obtain exact information on the efficiency of their campaigns, reports news agency Efe. The first ad drive will be for Orange's Fusion range. The service will be limited to the first 15,000 customers to sign up.