Abstract: A method and apparatus for allowing the collection of information regarding visits to the pages of a data network such as the Internet, and the number of separate images viewed is described. The described method overcomes various prior art limitations including providing for improved accuracy in reporting the number of times a banner image, such as an advertisement, is viewed; providing improved methods and apparatuses for efficiently identifying unique banner images viewed; providing an improved method and apparatus for configuring a network user's computer so that interference from the data collection process with the normal operation of the computer is minimized; providing an improved method and apparatus for efficiently calculating a checksum to allow unique identification of a banner image viewed by a network user; and providing an improved method and apparatus for determining whether the network user used the browser BACK button to view a page and, if so, to count the banner images viewed.

Abstract: An intelligent network agent intercepts transactions between clients and servers to perform Distributed Information Logistics Services (DILS) functions such as automatically retrieving updated files from remote servers and delivering them to local client programs. For example, HTTP clients and HTTPD servers are connectionless and stateless, thus there is no way for a server to update a browser automatically when an HTML document is changed. The invention provides a method to update any number of clients from any number of servers without making any changes to currently existing HTTP clients or HTTPD servers. Furthermore, the invention can provide various other DILS services for clients to reduce latency and communication costs for members of a group with interests in similar objects.