Every month, the NPD Group releases a report on the previous month's US sales in the game industry, both consoles and software. While that monthly report is already "projected to 100% of the market," according to NPD Group's David Riley, next month, it'll get bolstered by the nation's largest retailer: Walmart. Despite being revealed this past February, the past several months of NPD reports haven't included Walmart's numbers.

"Our enhanced retail coverage, including the addition of several new retailers, begins with May data released on Thursday, June 14," Riley told me in an email yesterday. While he couldn't supply a list of all of the retailers involved, he told me, "Yes, it does include Walmart."

With any luck, the addition of Walmart to NPD's stable of retailers reporting – which already includes America's largest game retailer, GameStop – will help to thwart claims of NPD being a "very poor indicator of the industry's performance." Then again, between the lack of digital sales accounted for in NPD's monthly report and the urge of publishers to spin poor sales numbers, those complaints likely won't stop anytime soon.

This article was originally published on Joystiq.