You'll be able to list up to the amount that the promotion provides throughout the duration of the promotion without impacting your normal number of monthly free insertion fee listings. For example, let's say you're a seller without an eBay Stores subscription who has been invited to participate in a 3-day promotion to list up to 100 items Auction-style free. So far this month, you've used of 10 of your monthly free insertion fee listings. Per the specifics of the promotion, you can list up to 100 items Auction-style free (no insertion fees) during the time of the promotion, and still have your remaining allotment of 40 free insertion fee non-promotional listings to use throughout the course of the month.