Well the "Sales Discussions" forum implies to me that any discussions dealing in sales should be in that forum. So I don't really understand how people can be confused about which forum to post in when they want to post a thread that discusses sales.
While the "Microsoft Discussions" and the description being "Xbox / 360, Halo, XBL, Live Arcade - keep it all in here!" seems to imply that the discussions are about products related to Microsoft. So I don't understand why some people think that means Sony or Nintendo products or comparisons.