TuneIn, a Web service that lets you listen to radio shows and podcasts from all over the world, for free, says it has 50 million users. But it would like many more, and it would like them to do more stuff when they visit.

So here’s a format change aimed at accomplishing that. TuneIn is trying to present itself as a social network, a la Facebook and Twitter, except that… [Read more on Re/Code]