The service is that he's making onlineradio.com available to you, for a price you both agree on. If he didn't, and someone else took it who wasn't a squatter then you would have no chance of getting it.
He's selling you a second chance to get the domain name, and a service of preserving the good domain names.
He's selling you a second chance to get the domain name, and a service of preserving the good domain names.