This paper proposed a support service to have better awareness to some values of commodities through natural behavior on a real world interface. We have developed a smart shop with ubiquitous camera sensors and communication robots; the former are to detect a user's (consumer's) behavior and the latter are to send multimodal message to a user to explain the value of the commodity. We found that the user's behavior on a commodity is closely related with the interest and/or preference to it. We have also shown that a multimodal message from a communication robot which exolain the value of a commodity way have an effect on the user's subjective evalution.