You can also earn the Flash base pack just for logging in regardless of whether or not you’re a member, and everyone can take part in the Flash Selfie Sweepstakes. Take a selfie of your character with any version of the Flash, upload it to Twitter, and maybe you’ll win some cash for the game. Just make sure to hurry it up; you don’t have that much time.
DC Universe Online would have an appreciation weekend for the Flash that shows up in the blink of an eye. The Flash Appreciation Weekend is running right now, and it ends on February 12th; you’d better act fast, or you’ll miss it. Fortunately, there’s not much you need to do, as just logging in will award Members with the Flash cowl costume piece. Not a member? That’s all right; becoming one this weekend will also award you the costume piece.
Source: Official Site. Thanks, Noel!