Recommender systems evolved in response to an increasing set of choices in products to buy and information to consume, combined with consumer frustration at a decreasing level of professional support for making these choices (i.e., fewer expert shopkeepers). These conditions created challenges for both consumers and merchandisers. Consumers experienced information overload and sought help in selecting from an overwhelming array of products while merchandisers lost their relationships with consumers and sought to re-build and deepen those relationships by better helping consumers find products of interest.