Abstract: Systems and methods for associating sessions using (TCP packet-level) timestamps are provided. A collection of data packets received during one or more sessions within a time period may be retrieved. Each packet in the collection may be associated with a unique identifier of a respective session. A skew for a selected session within the time period may be determined based on a rate difference between a respective receiving device clock and a respective sending device clock of at least two data packets associated with the unique identifier of the selected session. The selected session may be associated with a computing device. An uptime may be calculated for each of the retrieved data packets based on the determined skew and respective timestamp information of the data packet. It may be identified as to whether each of the calculated uptimes matches a previously calculated uptime for a packet associated with a previous session or a session that has previously been associated with a selected session.

Abstract: Systems and methods for session-based matching of mutable browser identifiers are provided. Information may be stored regarding a plurality of mutable browser identifiers each unique to an associated website and one or more maps each associating a immutable browser identifier to one or more mutable browser identifiers. Such a immutable browser identifier may be unique to an associated browser. Further, information may be received from a computing device that has used a browser to download a website. Such downloaded website may include a reference to a mutable browser identifier specific to the downloaded website. The referenced mutable browser identifier may be identified as corresponding to one of the stored mutable browser identifiers. The session information of the referenced mutable browser identifier in the received information may be compared to the session information of the corresponding stored mutable browser identifier.

Abstract: A webpage may be downloaded by a browser at a computing device. Such downloaded webpage may be associated with a reference to a browser identifier file. The browser may be directed to access the referenced browser identifier file. As a result, the browser may automatically check a local browser cache for the referenced browser identifier file. A request regarding the referenced browser identifier file may be sent over a communication network to an identifier server. Such request may be indicative of whether the referenced browser identifier file is found in the local browser cache. A response may be received from the identifier server. Such response may include the referenced browser identifier file when the referenced browser identifier file (or a current version thereof) is not found in the local browser cache. Alternatively, the response may include an indicator when the referenced browser identifier file is found in the local browser cache.

Abstract: The present invention relates to methods and apparatus for unobtrusively determining previous actions and information associated with a user via an RGB string and generating web page content based upon previous actions and stored information.