Can you clarify how this would work? If I reside in Florida/Hawaii and send mail to Alaska I am presuming that it would get re-routed through intermediate stop

Can you clarify how this would work? If I reside in Florida/Hawaii and send mail to Alaska I am presuming that it would get re-routed through intermediate stops. Also people move and mail traffic ebbs and flows through the seasons. So I don't understand how this subsidies would work unless we look at the network as a whole and budget accordingly.