As was mentioned in the WWDC 2013 keynote, the forthcoming iTunes Radio will feature a dedicated Twitter #music station. The Twitter #music station will allow users to listen to trending songs that are shared on Twitter with an option to buy the songs via the iTunes Music Store.
But as The Verge points out, iOS already has a dedicated Twitter #music app that is struggling to gain popularity. The agreement between Apple and Twitter to include a dedicated Twitter #music station obviously works out well for both companies. Apple gets access to social feeds from one of the most popular social networks ever, including increased revenue streams from users who buy tracks from the Twitter #music stream. But Twitter may be the biggest beneficiary in the agreement as inclusion of a dedicated Twitter #music station gives the company's fledgling music service an increased awareness to hundreds of millions of users.