Abstract: The invention provides, in some aspects, a digital data system for automated customization of digital content delivered over a network based, e.g., on measures of content appeal and/or user motivation. That content can include web pages, downloads, or other digital content accessed by a client digital data device (e.g., on behalf of a user) from a server digital device. Such a digital data system can comprise a server digital data device that is coupled to a plurality of client digital data devices over a network such as, for example, the Internet. A server application executing on the server digital data device responds to requests received from the client digital data devices for delivering thereto requested digital content.