A reactive label is capable of reacting with a shopper that peruses the label while considering the purchase of the labeled product. The label includes sensors (8, 9) and a display unit(5) and is powered by incorporated batteries or photovoltaic cells (7). The sensors can include a timer that provides the shopper with additional information from a ROM by displaying it sequentially on an LCD screen or the like. The sensors can also include a sensor such as an optical sensor that measures such factors as hair reflectance and can inform the shopper as to the suitability of the product (if, for example, it is a shampoo) for their personal use. The reactive label gives the shopper a previously unattainable sense of product personalization and will thereby enhance a sense of loyalty to and confidence in the product.