A system comprising:
units of a commodity that can be used by respective users in different locations,
a user interface, which is part of each of the units of the commodity, configured to provide a medium for twoway local interaction between one of the users and the corresponding unit of the commodity, and further configured to elicit, from a user, information about the user’s perception of the commodity,
a memory within each of the units of the commodity capable of storing results of the two-way local interaction, the results including elicited iriformation about user perception of the commodity,
a communication element associated with each of the units of the commodity capable of can"ying results of the two-way local interaction from each of the units of the commodity to a central location, and
a component capable of managing the interactions of the users in diflerent locations and collecting the results of the interactions at the central location.