The Spring Cocoon in Shenzhen seats 45,000 for a concert. AsiaWorld-Expo seats 13,500. Standing on the platform at Admiralty MTR last week, I heard a touring logistics coordinator explain the routing math in Cantonese to someone younger on the same crew: Shenzhen first, fill the stadium at prices a mainland audience will pay, then hold the Hong Kong date for fans who treat the smaller room as a luxury upgrade and will pay HKD 3,500 for a floor ticket without a complaint about the acoustics. The arithmetic closed the explanation before the train did. HKD 3,500 closes the argument.

Acts routing through the GBA now run a two-column ledger: Shenzhen for capacity, Macau for revenue-per-head. The Spring Cocoon's Longhua district ground-rent deal is structured as a venue-share rather than a flat rental, which means an act playing to 40,000 in Shenzhen splits ticket revenue with the district government rather than paying the upfront rental that Singapore Indoor Stadium or Hong Kong's AWE charges; the math favors the act, it favors Shenzhen, and the mechanism is a government subsidy dressed as a partnership agreement. Macau closes the second column: the casino IR theaters at Studio City and Morpheus run acts on guaranteed-audience economics, the resort buys the seats for VIP program guests, and the performer collects a flat MG with no relation to market demand. The venue-share is the mechanism.