Take-Two Interactive has claimed to have sold over five million copies of Borderlands 2 to date. This figure includes games sold by retailers and via digital stores, which basically are Steam and PSN.
Borderlands was released in mid of September and was accepted gladly by the masses. The game shot straight up selling around 1.8 million copies in it’s first two weeks in the US alone.
Currently developer Gearbox is in the process of releasing DLC packs for the game. There are four content packs featuring new campaigns, enemies and areas. A Season Pass is currently available for players through which they can get access to all the DLC at a discounted rate.