Red in STL
Turnover not takeover
The biggest factor is probably the fact that most teams have no local competition, most teams are the only pro team of a particular sport .in the metro area of a city, therefore the whole area supports 1 team, teams also do their own TV deals and the bigger markets share some revenue with the smaller onesThere are several factors but overall they are extremely profitable in general in an extremely big (ie. tons of cash in the pot) market and not comparable at all with sports teams as you know them (that very well could change in the future). Add to that the significant rise of billionaires in America and the battle for being part of the exclusive billionaires club that own sports franchises and you got a recipe for a meteoric rise in asset value.
Using baseball as an example, St Louis Cardinals biggest rivalry is with the Chicago Cubs and to a lesser extent the Kansas City Royals, those are the 2 nearest teams to St Louis in MLB and both are 300 miles away