Okay, that’s going a little overboard, but over at Kotaku Brian Crecente adds to my questions about how accurate NPD’s numbers of game sales are. He confirms that NPD’s information reflects about 60 percent of U.S. retailers. But here’s a big asterisk: their numbers don’t include sales at Wal-Mart.
That makes the 60 percent claim seem fishy. Is it 60 percent of the retailers in the country, i.e. data from a certain number of retailers? Or is it retailers who sell 60 percent of the video games in the U.S., i.e. data from a certain proportion of sales in the country? It’s a big difference. According to this story in The Nation, Wal-Mart controls about a quarter of the U.S. music market. It’s a good bet Wal-Mart has at least that much of the country’s video game business (if not more since there are far fewer game retailers than music retailers). So if NPD gets data from 60 percent of the retailers not including Wal-Mart, that means they’re getting data about only 45 percent of the sales (60 percent of the remaining 75 percent of sales). If NPD really means it’s data represents 60 percent of the actual sales, that’s different. But that Wal-Mart exception makes me suspicious.
There still might not be anything ultimately wrong with NPD’s numbers. As commenters point out in Crecente’s post, sampling and “sophisticated projection methodology” can still yield accurate results. And the game companies themselves rely on the data; if there were big problems, they’d surely have switched systems by now.
Still, it doesn’t make sense that there’s no video game equivalent of Nielsen SoundScan or the box office data that records actual sales at the register. (I don’t know if Wal-Mart also shuts out SoundScan, but it seems unlikely given how important the retailer is for music sales.) TV ratings are based on samples for reasons of vested interests (that of local affiliates) and privacy (though I believe people are more open to anonymous tracking than they used to be). There’s no good reason why video game sales should be tracked like TV viewership.
— January 19, 2007