You asked for more Triple XP and so we shall oblige... By popular demand, this coming weekend, every Red Dead Redemption and Undead Nightmare multiplayer mode will yield you XP times three. It all begins tomorrow, Friday morning August 12th around 12:01AM Eastern (4:01am GMT) and doesn't end until Monday morning August 15th.
From Rockstars Facebook page.
triple XP all weekend long. It dont say if its for PS3 or XBOX but im assuming its for both, Have fun!