The NPD Group has warned analysts that they are not to supply any confidential sales data to the media, as it continues to tighten access to publicly available information.
The company recently removed sales figures from its monthly reports and now only releases a top ten of best-selling games in the US without solid numbers. It has also stopped reporting hardware figures, although individual manufacturers are free to release the data.
Going further, NPD has asked that analysts remove members of the media from their mailing lists and not discuss stats with reporters or outlets.
Companies such as Wedbush Morgan and Cowen & Company include select NPD sales figures in their regular notes, informing investors of the performance of publicly traded games companies such as Activision, Electronic Arts and Ubisoft.
NPD has most recently been criticised for not providing a realistic picture of the digital sales landscape in the US, but it told GamesIndustry.biz recently that it is putting plans in place to closely monitor the market and report with monthly information.