Minecraft continues to be a sales juggernaut. In fact, the Xbox Live version has just recently crossed the four million mark. Not to be outdone, the PC original can now be purchased at retail stores.
Mojang announced that prepaid Minecraft cards are being sold in Wal-Mart, Target, and Best Buy stores. For the time being, only US stores are selling the cards. They're download codes rather than retail discs, so this really only helps if you wanted to pay cash for your Minecraft. On the XBLA front, 4J Studios announced the 4 million number via Twitter.
Minecraft has sold more on the PC, currently ticking above 7.5 million copies. Then again, the PC version has been on sale for much longer, so it's hard to say which game is really winning the race. Any way you slice it, though, Mojang and 4J Studios are cleaning up with the block-building title.