In the smartphone wars, Blackberry is a distant third to iPhone and Android devices. With much of the iPhone and Android marketing focus on their ability to handle music and video, Blackberry is developing a cloud-based music application. The subscription service is expected to cost around five dollars a month, and will allow subscribers to build a personal music library (based on digital locker concept), as well as building a personal profile of 50 songs to share through the Blackberry BBM social networking service.
The move to the cloud is a good idea, as it allows expansion of media-based uses and applications without having to upgrade memory levels in the access devices. I suspect, however, that it's overall impact as a marketing tool will be limited - the service is tied to the device, limiting its overall usefulness, and the price level is higher than a number of other cloud-based, or IP-based music streaming services that can offer access to a much wider music library and/or the ability to access music from a range of platforms.
Source - Blackberry users get cloud-based music locker, Telecoms.com