Free credits refer to a bonus balance assigned to sellers that can be used for ad campaigns instead of the seller's cash-on-delivery balance. Sellers can view their free credit allocation and transaction history on the seller portal. The rewards page allows filtering transactions by payment type (cash-on-delivery balance or free credits) and shows details of ad campaigns funded by each. Free credits have expiry dates and any remaining amounts are returned if a funded campaign is aborted. Ad campaigns first deduct from free credits then the cash-on-delivery balance.