One interesting use for Scheduled Bulk Ops is to implement a product launch sequence. In this scenario, you would create a campaign and add your launch emails, but not add any subscribers. Instead, you would tag subscribers whom you want to receive the launch emails (with e.g. “September launch”).
Once you know your launch date, create a scheduled bulk operation to subscribe anyone tagged with “September launch” to the launch campaign a few minutes before you want the first email to send.
Tip: It can take up to 15 minutes for campaign emails to begin sending, so if you want to target an exact launch time, configure the first email of your campaign to only send on a certain day of the week (e.g. Tuesday, 11am), and scheduled the bulk op to add subscribers Monday evening. This will help ensure the first email goes out at the scheduled time.