It really comes down to the product/service and communicating that in the message...the radio spot must make a connection to the listener and their needs.  So many so-called "branding" spots read like an audio brochure, but never really provide any reason for people to buy.  In other words, they don't really offer anything unique that would make a potential customer choose company X over company Y.  

Remember...advertising is only one facet of marketing.  

Great article!

M. Bruce Abbott
Creative Director/Partner
Radio Lounge
http://www.radioloungeusa.com