"To earn your reward, play the Destiny Beta on Saturday, July 26th at 2pm PDT (9pm GMT)," the message reads. Bungie did not specify what the reward is, but free is free, so be sure to hop on this weekend if you're intrigued. Here's hoping that it's a gold-plated Peter Dinklage-bot. Or new character dances. Or a dancing Dinklage-bot.
[Update: Bungie confirmed that the featured reward is an in-game emblem.]