Warner Music Group has announced that MTV will now be the exclusive seller of advertising content around its music videos online and on mobile. The deal covers MTV’s own sites and mobile services, but also WMG artist sites and third-party sites. “This alliance enables us to offer our artists the marketing and sales firepower of the world’s most widely-recognised and highly-trafficked music destinations,” says WMG’s Lyor Cohen. The news further separates WMG from the other major labels, who are focusing on their joint venture, Vevo. It’s not entirely clear how this affects WMG’s existing partnership with Outrigger Media, which sells ads around WMG’s videos on YouTube.