Bungie launched Destiny‘s recruit a friend campaign, allowing players and their recruited buddies to earn rewards together.
The campaign is available here, and it springs into action once your invited friend buys and activates his copy of the game on the same platform as you.
The first step prompts you to complete a mission with your buddy, named The Hunt for Loot. Further rewards include the Elemental Kinblades swords, the EV-34 Vector Infinite sparrow, the Duo Dance and High Five emotes, the Infinite Link Shader, and the Sign of the Infinite emblem.
You can check out a trailer of the campaign below.