According to data provided by developer, Mojang, one copy of the €9.95 ($13) game is currently being purchased every 3 seconds, representing sales of $15,000 per hour.
Minecraft drops the player into a vast, pristine, and hostile world in which they must build tools and find resources in order to survive. The focus is on gameplay, and graphics are deliberately crude. Both single player and multiplayer versions exist. In the multiplayer version, players are free to either collaborate or compete.
Minecraft had been selling more than 4,000 copies a day for several weeks, but sales spiked to new highs after a server meltdown prompted Mojang to offer the game for free over the weekend. Many of those who tried the game, which has been dubbed 'Minecrack' for its addictive quality, obviously liked it so much that they purchased it as soon as the servers came back online on Wednesday.
Indeed, Mojang has quite a habit of finding triumph in adversity: an earlier bump in sales was apparently triggered by publicity surrounding Paypal's decision to temporarily lock Persson's account because the amount of money flooding in was deemed 'suspicious'. Sales grew to over 6,000 a day during this period.
"It all feels unreal. I thought I could make a living from the game, but I did not expect to become rich", Persson said in an interview with IDG. Persson was courted by major games companies, including Valve and Bungie, during a recent visit to the US, but said he was not interested in job offers.
The game relies on open source sound and graphics code, notably the Lightweight Java Game Library (LWJGL). Persson's use of the Java programming language has made the game easily portable. Versions of Minecraft are available for PCs, Macs and Linux. It is playable on relatively low-powered systems such as netbooks, although graphics can be jerky on such machines.
Perrson cites games such as Dwarf Fortress, Dungeon Keeper and Inifiniminer among key influences on Minecraft's anything-goes nature and blocky 8-bit style.
While it is obviously popular, Minecraft is far from complete, Persson says. The game is still in heavy development, with the current version labeled an 'alpha', and a 'beta' version planned for the near future. Persson plans to double the price to €19.95 when the game is finished, but a purchase of the current version includes all future versions.
Correction: This article originally gave the price of the game as $10. The actual price is €9.95 Euros (about $13.30)
Update: This site has archived recent sales data for the game. Sales for September 22 reached almost 26000 copies, representing revenue of almost $350,000 for that 24 hour period.
Update: Persson plans to release the beta version of Minecraft by the end of the year, at which time the price will be increased to €14.95.
Update Sept 29: Since reaching a peak of almost $350,000 in one 24 hour period, on September 22, Minecraft has been selling well over $100,000 every day, despite server outages that have sometimes prevented sales or registrations. Note that because Persson resides in Sweden, these impressive revenue numbers are obviously going to be subject to Swedish taxes to some extent (very approximately 25% for business income, and almost 60% for personal income at the highest rate).