Hello @nitrat:
From a documentation article titled ‘Create Your First Popup’ (recently added to our docs):
3) Set a content-based condition to activate the popup (optional). [See the ‘Conditions’ box in the Popup Admin]. If you don’t set a condition, the popup will activate on every page of your site.
We recommend setting a content-based condition using the ‘Page Selected’ >> {exact-name-of-page} option whenever possible. It’s easier to read, maintain, and troubleshoot.
Activation preloads the popup in the footer on page load in the browser. It is a ‘potential state’, necessary to prepare a popup to display, but not sufficient to actually show it in the browser.
Related article: Conditions Introduction.