Honestly, I never really cared much about the "niche" nature of the hobby, a lot of my interests are not shared by most people and it doesn't make much difference. And yet, seeing a D&D book continue to be one of the best selling books in the country is pretty darn cool.
Just went to look what books were in the same ranking, a "1984" paperback is sitting higher, along with 3 newer books which likely wont stay there too long.
They actually went up a bit;
PHB #5 .ca! #51 .com
and the DMG is at #16 in Canada
Really wonder what drives these little ups and downs.
PHB has 1871 reviews @.com, 285 @.ca