Editing the priorities by which the popups appear can come in handy if you have multiple popups installed on the same page with the same parameters, and you want them to be shown to the visitor in a certain order.
The prioritization menu can be found under Widgets by clicking the Edit popup priority button.
The priorization menu lists all your popups (note: even the inactive ones) and shows you when they were created. You can rearrange them by dragging on the three bars on the right side of the popup, and dropping them to the desired spot.
After you have the popups in order, remember to click Save popups near the bottom of the window.
After this, the priorities can also be seen at a glance in the Widgets page, next to the creation date on the right.