This is a PSA, since many people here want to visit the Anne Frank House museum.
From May 1st, you will need to book a time slot for you visit, buying a ticket online in advance. The rule applies to visits up to 15:30. There is a 30-min window for you to enter the museum, but no limitation on how much time you can spend inside. After 15:30, people will be allowed to queue up and buy tickets at the window.
The measure intends to curb the long lines and improve visitor experience.
More info here: http://www.annefrank.org/en/Museum/Practical-information/Online-ticket-sales/
I'm happy with this new system, I think it is the future for all busy museums, nothing is more wasteful while traveling than standing on long lines to gain admission to museums, monuments etc.