When I was lurking the ole NeoGaf forums I stumbled upon this little tidbit: D4 sold less than 10k in late September.
It's quite a damn shame that D4 is kinda in the gutter at the moment. Personally, I was planning to get it on PC in a similar vain to the other xbone exclusive DR3.
Hopefully, this game would pick up some steam with some help from actual marketing from Microsoft and/or popular gaming personalities.
SWERY's twitter : https://twitter.com/Swery65
Topic/Giveaway thread link: http://www.neogaf.com/forum/showthread.php?t=902813