Gecko Corp. sent Watson Co. a purchase order for 100 Watson compasses for $2,500. Watson accepted Gecko's offer by sending back an acknowledgement form. However, Watson added a clause providing for interest on any overdue invoices pertaining to the sale, a practice that is standard within the industry. If Watson and Gecko are both merchants and the parties do not communicate further about the terms, is a contract formed that includes Watson's additional term regarding interest? Explain why or why not.