Systems and methods for monitoring transaction data in a point-of-sale (POS) system. An inline component is connected between a POS terminal and a printer. The inline component monitors communications between the POS terminal and the printer as well as communications sent to or from other devices connected with the POS terminal. As the data in the communications are monitored, portions of the data are extracted and sent to a remote processing server. The remote processing returns information which could comprise a variety of information, such as: fraud deterrent data, store promotions, customer messages, and the like to the inline component. The inline component sends this information to the printer for presentation to the user. The information is typically sent to the printer without interfering with the transaction being performed by the POS terminal. Commands included in the information can be implemented by the inline component.