Sony Corp. (NYSE:SNE) is clearly winning the current console war with 10 million PlayStation 4 units sold since November. Data released by Nielsen gives some insight into the reason: owners of other consoles have been jumping ship to the PS4.

According to an April Nielsen study, 31 percent of PS4 owners didn't own the PlayStation 3 but owned a Microsoft Corp. (NASDAQ:MSFT) Xbox 360 or Nintendo Co. (TYO:7974) Wii, Recode reported Wednesday.

The study, conducted between February and April, surveyed Americans age 7-54 who comprised a subset of 1,200 "active gamers." While the number would seem to explain the PS4’s lead, Recode notes that the study has a caveat. It asked gamers what they “currently” owned at the time, which would classify those that traded in their PS3 for a PS4 as non-PS3 owner.

While it’s unknown how much that may affect Nielsen data, if the 31 percent of PS4 owners recorded consisted mostly of users of only other video game consoles, the numbers would reinforce the PS4’s apparent advantages over the Xbox One, including its $399 retail price, $100 less than the Microsoft Console.

The number of previous PS3 owners represented in the Nielsen data could also be lower, since PS3 owners have often held onto the console thanks to its extensive library of nearly 800 titles and free games offered through the PlayStation Plus subscription service.

Games offered on the PS4 and Xbox One are unlikely to give more insight into the attrition to PS4 since NPD Group’s retail charts list cross-platform games such as “Call of Duty: Ghosts,” “Battlefield 4,”  “Madden NFL 25” and “Assassin’s Creed  IV: Black Flag” as top sellers of 2013.

While Sony is more than happy about the PS4’s dominance in the console wars, they profess to be baffled as to why. “I for one am a bit nervous because we do not completely understand what's happening.” Sony Worldwide Studios President Shuhei Yoshida told Eurogamer “You need to understand why your products are selling well so you can plan for the future, right?”