Hi Russell, you can make FancyBox open on specific URL hashes. Assuming you already have your popups ready on a particular page and each one can be opened by clicking a specific link on that page, follow the following extra steps:
Go to Settings > Media and find the option called Open on page load under Miscellaneous / Auto popup. Set this to Link with ID matching URL hash and save settings.
Go back to the page/post where your popups should appear and if the media/popup links do not already have a unique ID (for inline content) then give each a unique ID, like id=”popup1″, id=”popup2″. Note that if your popups are inline content popups, then they should already have a unique ID and you do not have to do this step.
Now test each popup by visiting your page in an anonymous browser window with #popup1 or #popup2 etc. appended to the URL. Each time, the corresponding link should be triggered, automatically opening the corresponding popup.
Redirect your users to these URLs (with different hash after them) to make the get a specific popup.