As a third-party SaaS, we count the number of visitors that reach the page where the UserGuiding script is embedded. If the same user with the same browser session arrives on the page multiple times, for instance, we count it as 1 MAU.
However, if the user changes its computer, starts a new browser session or clears the cache and/or local storage, we consider it as a new user since there is no way left for us to understand if s/he is the same user or not.
That said, User Persisted Storage is a solution we offer to keep the data persisted in the cloud.
When this feature is enabled, user ids, guides played, guides completed, step analytics and segmentation &custom attributes are kept in the cloud and accordingly retrieved each time an end user visits your website.