While GEICO remained radio's number one advertiser last week according to Media Monitors with 44,575 commercials aired across the country, two wireless companies made decent jumps on the list to enter the top five. MetroPCS was number two with 29,626 spots and Boost Mobile was number three with 27,710 spots. McDonald's was fourth with 26,819 and O'Reilly Auto Parts was fifth with 21,601.
