How to increase the impact of Open Monumentendag?

Each year, and this year for the 30th time already, this large-scaled public event is being organized by Herita. Counting the number of visitors on an event like this, with more than 1.000 activities on 600 locations spread all over Flanders, is a huge challenge. The aim of our workshop with this organisation today is to link our recommended counting method  to methods for increasing the strength and impact of Open Monumentendag.