Blizzard decided to get in on the action again this year by cutting the price on some of its games last week as part of a Black Friday Sale promotion. The games on offer included digital download copies of World of Warcraft and StarCraft II.You could pick up World of Warcraft for $4.99, a $15 saving, and the Mists of Pandaria expansion for $9.99 (usually $39.99). For StarCraft II: Wings of Liberty, the base game was reduced from $39.99 to $19.99. Heart of the Swarm also got the same discount down to $19.99. Digital Deluxe editions for both games also got a nice price cut.That sale was only meant to last until Monday, but the Battle.net post has been updated to announce that the promotion is being extended to January. You’ll now be able to enjoy the cheaper pricing until 11:59pm PST on January 1st.This extension is probably a reaction to two things: masses of players leaving World of Warcraft this year and the boost in game sales such a large price cut brings.As I have said before, the majority of the money Blizzard makes on WoW doesn’t come from the initial game sales, it’s the subscription players pay every month. If a $5 copy of the game bumped subscriptions to the game up a few thousand last week, it makes perfect sense to keep offering it for the rest of the holiday season.The same logic works for StarCraft II. Anyone who enjoyed playing previous StarCraft games purchased Wings of Liberty ages ago. Sales like this bring new players, and those players are more likely to purchase new entries in the StarCraft series in future and at higher price points if they find they enjoy playing the game.