I’m listening to Your Mac Life, a live radio show that is (as far as I know) only broadcast online. The show quality is great–it’s entertaining, the audio is clear and crisp, and really, it’s comparable if not better than a lot of what you hear on talk radio, both AM stations and morning shows. (Here in the US).
I’m not aware of any similar, web only, talk radio shows, but from all I can tell, they are probably making a profit on this. It seems like a feasible business model–they are targeting a very specific, tech-savvy group of listeners who most likely fall into a high income bracket. They appear to have quite a few sponsors on their site, and the commercials (there aren’t many at this point) seem to be professionally done.
Lots of people are looking for a way to make money online, and I think that this is one of the few content delivery areas that has yet to be saturated.
I found their site from a link to the Pepsi iTunes giveaway superbowl ad. You can see it in it’s entirety on their site now. Check out the ad. It’s cool (Quicktime, a few Mb).