Hangouts is more than just a video conferencing tool. It also offers a global soapbox via its Hangsouts On Air feature, which lets you stream live Hangout feeds to people who follow your Google+ profile, YouTube channel, or website. Naturally, Hangouts On Air is a boon to musicians and other live entertainers, but it's useful to businesses too, including those that want to demo a new product or service.
What if nobody watches your live stream? That's a real concern, of course, but because Hangout On Air events are automatically recorded and uploaded to your YouTube account, your Google+ followers can catch them later.