These days fewer and fewer people have access to radios in the workplace, but where radios are lacking, computers are plentiful. These at-work listeners are technically savvy, like to buy online and have disposable income to do so. This is an audience that your advertisers are probably very interested in reaching and you should be as well. Here are some statistics on the demographics for those who listen to online radio:
From the Arbitron/Edison Media Research study "The Infinite Dial 2008: Radio's
Digital Platforms AM/FM, Online, Satellite, HD Radio and Podcasting."