Every ticket you buy has a time and day- a 15 minutes period in which you may enter. And there are a limited number of tickets per 15-minute period.
This does mean you have to plan your visit ahead by a day or two, but you'll be rewarded with not needing to line up for more than a few minutes.
Operationally, the management have an exact steady stream of visitors from open to close, so staffing can be just as even, which I can only imagine reduces costs. And management can also tell if they've priced entry correctly by seeing if they have open spots all week or having three weeks' backlog sold out.
Could we please do this for everything that has a line up? It's a wonderful system.