An online merchandising and promotion system is disclosed that closely simulates an interior space of an actual place of business in a virtual reality world. The outer member includes a cup section having track grooves formed therein, and a shaft section having one end coupled to a bottom portion of the cup section. The transistors are electrically connected to the bias voltage circuit to thereby control the steering direction of beam radiation by switching the transistors. The beaconing responsibilities may be shared on a round robin basis or may be shared according to the operating characteristics of the wireless devices with some wireless devices assuming greater beaconing responsibilities than other of the wireless devices. The present invention provides a method for producing megakaryocytes from hematopoietic progenitor cells, comprising forcibly expressing an apoptosis suppression gene and an oncogene in hematopoietic progenitor cells and culturing the cells, and arresting forced expression of the apoptosis suppression gene and the oncogene and culturing the hematopoietic progenitor cells. At least one of the pair of sealing portions is provided with at least one constricted portion whose length in a thickness direction of the metal foil in the sealing portion is smaller than that of other portions in the sealing portion.