How will recommender systems that are serving marketers evolve to protect the trustworthiness that makes them valuable to
customers? Recommender systems emerged as agents to help customers find products to purchase. These recommenders were
implemented by sites to create additional value for their customers, so those customers would be more loyal to the site. Now, some
recommenders are evolving towards marketing systems that help sites sell high profit products. One way to counter this evolution is
to create verifiably unbiased recommender systems that consumers trust to recommend on their behalf. In the mid 1990s Firefly
proposed creating such a branded recommender system. Consumers may be suspicious that an unscrupulous Web site might modify
the outputs of such a recommender before displaying them. How can a trusted recommender validate itself to consumers through a
Web client? Is it possible to build portable recommenders that can run on consumer’s palmtop computing devices, serving only the
consumer?