The purpose of this setting is to prevent duplicate input URLs from being processed twice in a workflow.

More specifically, it processes unique profile URLs in your campaigns when you schedule a list to run every day, for instance.

Ex: Avoid sending twice a message or a connection request to the same profile when reprocessing a Google sheet or search filter input when scheduled to run a regular interval.

So when you do a drip campaign with follow-ups or send connection requests, please activate this option.