The World of Warcraft expansion pack Wrath of the Lich King has become the fastest-selling PC game in history after moving 2.8 million copies in 24 hours.

Gamers all over the world waited in long lines to buy Wrath of the Lich King, a new expansion pack for the popular computer game World of Warcraft. There are 11 million players worldwide on WoW, more than the combined populations of Costa Rica and Nicaragua.

Video game companies Activision (Call of Duty) and Blizzard (World of Warcraft) are combining forces in a $18 billion merger.