An oversell occurs when there is a delay in communication between an integrated Sales Channel like TCGPlayer, Amazon or eBay’s servers and Crystal Commerce’s servers.  This is an incredibly rare occurrence with our system.  Realistically, there is a small risk of overselling on any integrated Sales Channel online so if you notice an oversell in your inventory, we suggest first trying to fulfill the order and contacting the customer to update them then contacting CrystalCommerce Support and we can investigate the cause of the oversell.