Zombie survival shooter DayZ is very popular it would seem. The game has sold over 800,00 copies in under a month after it hit Steam following a successful Greenlight campaign. It is estimated to have netted developer Bohemia Interactive a cool $24 million (minus Valve’s cut of course). The game began life as a mod for ARMA II but now has standalone release in early alpha. A member of the DayZ dev team took to Reddit to express his amazement at the games popularity and hinted that this explosion of sales will speed up the development process.