http://en.wikipedia.org/wiki/Zune_Software#Zune_Marketplace
The choice of branding and distribution were part of the Zune as a decision of "two strategies in the market right now: cross-brand ecosystems... and singular brand ecosystems... The former is gaining in share and units sold, but the latter has enormous share and won't give that up easily."[38]
Microsoft normally follows a platform (cross-brand) strategy, as exemplified by the PlaysForSure system. However, its Xbox division has gained some experience with the vertically-integrated strategy in which it controls everything end-to-end from the hardware to the online store. With Apple dominating the audio market with its vertically-integrated iPod system, the Xbox division won permission to try the same approach, separately from PlaysForSure and PlayReady.
Microsoft also wanted to go beyond Apple’s efforts and promote the tagline "the social" and Wi-Fi (wireless sharing) as key differentiators. Chris Stephenson, leader of Zune's marketing and manager of Global Marketing for the Entertainment Business,[60] said, "we see a great opportunity to bring together technology and community to allow consumers to explore and discover music together."[38] New York Times Magazine columnist Rob Walker agrees that the Zune's "community and togetherness seem like a reasonable counterpunch to iPod's supposed attraction as an individuality enabler that allows owners to wallow in their own tasteful personal soundtracks." But he also sees the Zune as having gained appeal as an individualistic statement against the omnipresent iPod: "The most salient feature of the Zune seems to be that it's not an iPod".[61]
I know... my english sucks
