“Internet Radio Makes Waves,” a new eMarketer report, predicts the radio industry will see double-digit losses in ad spending this year alone, with terrestrial radio bringing in $14.5 billion in ad revenues in 2009, a drop of 18% from 2008 levels.

ZenithOptimedia reports that in 2009, advertisers will spend $260 million on Internet radio and another $28 million on podcasting for a combined total of $288 million, up 28% from 2008. By 2011, that combined figure will reach nearly $394 million.