A file replacement system includes a storage device, a host, and a server. In a file replacement transaction one or more files that are stored in the storage device are replaced in the storage device by one or more files that are provided by the server. The storage device monitors access to the files stored therein and updates an access tracking table with segment access information that pertains to access to segments of the files. While the file replacement transaction is in progress, the storage device delivers the segment access information to the server, and, based on the segment access information and file replacement criteria, the server determines a credit to which the end-user is entitled for the replaced files. The server calculates an outstanding balance for the file replacement transaction from the credit owing to the end-user for the replaced files and from the cost of the replacement files.