A closed league adds teams only when the existing owners agree. That is not a formality, because every new franchise reduces what each current owner receives.
Central revenue is divided by the number of teams
National broadcast money and league-wide sponsorship are pooled and shared. Adding a team means the same pool is cut into more pieces.
Unless the new market increases the value of the next media contract by more than the dilution, existing owners are worse off.
The expansion fee exists to bridge that gap, and it is distributed among the current owners as compensation for the dilution.
The fee is a purchase of membership
What a new owner buys is a share of the league itself, including its future revenue streams and its governance rights.
Because those rights are perpetual, the fee is benchmarked against what existing franchises trade for rather than against the cost of building a team.
Values rise when media deals are strong, which is why expansion conversations cluster around the negotiation of new broadcast contracts.
Voting thresholds are deliberately high
League constitutions typically require a supermajority of owners to approve expansion, so a determined minority can block it.
The threshold protects owners in markets that would be affected most, particularly those near a proposed new city.
Territorial rights are a separate consideration, and a new team placed close to an existing one may require compensation to that franchise specifically.
The new team has to be stocked
An expansion franchise begins with no players, so rules provide an expansion draft in which existing teams expose part of their rosters.
Protection lists limit what can be taken, and the number of protected players is negotiated alongside the expansion terms.
Draft position and salary-cap treatment are also adjusted, since a team with no roster cannot operate under ordinary rules in its first years.
Labour agreements set outer limits
Player association agreements affect expansion because roster spots, revenue-sharing percentages and cap calculations are all governed by them.
More teams mean more jobs, so players generally favour expansion, but the terms have to fit within an existing agreement or be negotiated into the next one.
Expansion therefore sits at the intersection of three negotiations: owners with each other, the league with a prospective owner, and the league with its players.

