Big box home improvement giant Home Depot retained its top spot as radio's number one advertiser last week (57,782 spots aired). However, as Media Monitors reports, Auto Zone rocketed to the number two slot, from 36, by airing nearly 36,500 commercials. GEICO is pushed down to number three (29,378), O'Reilly Auto Parts climbs one spot to number four (26,410) and McDonalds rounds out the top five (26,249). Two wireless carriers made big gains last week. Verizon moved from 48th to 7th (24,694) and Metro PCS jumped from 39th to 8th (23,072)
