The NPD has revealed the lifetime retail sales numbers for World of Warcraft at US retailers, and, unsurprisingly, the figures are absolutely gigantic.
It's safe to assume that World of Warcraft has sold quite a few copies at retail in the US. Now we can add a number to that assumption thanks to the NPD, who have revealed the lifetime sales figures for WoW to Gamasutra. Counting every single version of WoW that's been released thus far, the series has sold a whopping 8.6 million copies to date.
That's including plain old vanilla WoW, the collector's editions, the battle chest set, and the two expansion packs. Gamasutra figured that, considering the prices of the plain game and the expansion packs nowadays, the average price per copy sold would be around $30. You can tweak that number a little higher if you want to average in the collector's editions, but regardless, if you punch that number into your calculator and hit multiply and you get a whole lot of digits: $258 million dollars in sales to date.
Obviously retail sales are only one half of the money making equation. Consider the dough raked in from monthly subscription fees and well, you're going to start hitting numbers that will make your head spin. And don't forget to factor in talking Murloc doll sales, either. Blizzard's making a fortune off those damn things.