The Hockey News' Ken Campbell recently posted a tweet indicating four of the five Canadian teams playing at home last Tuesday — Winnipeg Jets, Calgary Flames, Vancouver Canucks and Montreal Canadiens — failed to sell out. He also pointed out the Ottawa Senators had huge attendance issues this season thus far.

Campbell observed it isn't good for the NHL when Canadian teams struggle at the gate. Those seven franchises are believed to generate around 35 percent of league revenue each season.

Unlike other major North American sports leagues, the NHL remains largely a gate-driven league.  Even with the current disparity in value between the Canadian and American dollar, Canadians' passion for the sport generates a significant chunk of hockey-related revenue. Any notable decline in attendance among those seven teams can be a cause for concern.

In a subsequent article, Campbell cited a Canadian sports market guru suggesting several factors, such as other emerging forms of entertainment or technology for watching games at home, could be behind the early attendance dip.