Hockey is a niche sport outside of a handful of countries. These countries are also very White historically and the game is expensive to play only compounding the problem if you are trying to market the NHL to a nonwhite audience. Add in the fact that stars are less marketable in hockey because their impact on the team is smaller than what American audiences are used to. Following from the aftermentioned Whiteness, the league is more rooted in a reserve style for player communication, which again makes it harder to market. All these factors compound each other and make it difficult for the NHL to market itself to the masses. The best bet for the NHL is continuing tapping into the European Hockey market while increasing efforts to make hockey more affordable and easy to play (think of the NHL cobranding gear that is inexpensive and of relatively good quality and donating large amounts to various rinks in each city a franchise is in), and seeing if they can get in on the ground floor of streaming sports via an outside content provider like Amazon or Netflix).