Existing online audio services offer some of what DAR.fm already does. Free services like Pandora replace the traditional experience of listening to radio stations for music. And they're better, since you get music more in tune to your tastes. If you want to listen to specific songs or just one artist, there are subscription services such as Rhapsody. Talk show listeners can get their tracks whenever they want via a podcast service, like iTunes.
So where does DAR.fm fit? Oh, and did I mention that since it picks up audio from radio stations, its audio quality is noticeably lower than other services ("sounds more like DAR.am," as elliotloh Tweeted)? Robertson is threading the needle with this business, but he does have a niche. First of all, it's free, and it gives you some of what you can only get when you pay for a service like Rhapsody: If you record your favorite radio station for a few hours, you can see all the songs played during that time and skip around to them by name, which you can't do for free with another service.
Second, it's legal, or so Robertson believes--and he does have experience battling the music industry in court. The radio stations can't compete thanks to copyright laws, and the legality of letting users record what they hear, even to a cloud service, has precedent.
Robertson also is getting his service baked into, or least working on, other products besides the browser: There are smartphone apps, plus it works on Roku, Squeezebox, and on some $150 Internet radios you can get at Best Buy, he says.
For me, the poor audio quality of DAR.fm is a stopper. For younger users, I'm not convinced that they hew to radio stations the way I did in my youth, which I think is another problem. But there may be a big enough user base who likes the new features DAR.fm offers to give it some wings. It does make saving radio shows easier than almost any other service.