Actually, “popularity” is more of a notion of sports sociology. Glad to clear it up.
Depends on what aspect of it you care about. In the business aspect popularity only matters in so far as it generates revenue, having millions of people like your thing in a way that doesn’t make you money means nothing. That popularity at least has to generate TV ratings, and preferably a lot more than that. It’s one of the reasons why the soccer business wants to be popular in America, nobody spends money on sports like us, 1 US soccer fan will generate as much revenue as 10 to 20 South American fans. Just look at how much ESPN paid for this World Cup (about $212 million) versus what they pay the NFL ($1.9 billion), and they let Fox “take” the World Cup contract for next time for the same amount ESPN paid. That’s the difference in popularly.