From July 20, 2011 through July 23, 2011, visit www.facebook.com/DCUniverseOnline for at least one clue per day, which you will use to uncover a secret webpage, which will contain instructions on how to enter for your chance to win one copy of the DC Universe Online DLC Pack, Fight For The Light, for either the PC or PlayStation3 computer entertainment system (approximate retail value, US$9.99).
Each entrant must have an active DC Universe Online account in good standing for the PC or PlayStation3 before July 20, 2011 to be eligible to enter and win a prize. Fifty winners will be randomly chosen from all eligible entries. All prizes are non-transferable and non-tradable.
Official Rules can be found here