Using cross-site relationships to generate recommendations

A system for providing recommendations of items to an end-user comprising:

• a processor to execute modules, including:
• a relationship observation module for observing relationships established by the end-user through interactions with a web site;
• a communications module for sending messages having relationship data describing the observed relationships to a relationship server via a computer network and to receive a message requesting recommendations for the end-user based at least in part on observed relationships described by messages sent by a plurality of web sites, the message specifying a label identifying an item, a predicate describing a type of the item and at least one constraint on one or more items to be returned as recommendations;
• and
• a recommendations module to perform collaborative filtering to identify a set of items related to the items identified in the message requesting recommendations and satisfying the at least one constraint.

A computer generated method of providing recommendations, comprising:

• receiving a message requesting recommendations, the message specifying a label identifying an item, a predicate describing a type of the item and at least one constraint on one or more items to be returned as recommendations;
• establishing a set of relationships by associating each component of relationship data with a unique identifier (ID), the relationship data including a label component identifying an item, a predicate describing a type of the item and an intent describing an action that established the relationship;
• generating recommendations of items by performing collaborative filtering to identify a set of items related to the items identified in the message requesting recommendations and satisfying the at least one constraint;
• and
• providing the recommendations to the an end-user.