Overwatch & Twitch Prime Guarantee Legendary Loot Boxes

From PVPLive.net

If you were ambivalent about whether or not to get a Twitch Prime account, this may be the deciding factor: for a limited time, you will be guaranteed a Legendary Overwatch item, along with ten regular loot boxes, for signing on. And because Twitch Prime’s got deals with a whole bunch of games, it won’t be the only sort of loot you get either.