An article by "The Wall Street Journal" indicated that K-pop's future staying power will be shaped by fans, whose online activities have evolved into "micro-businesses". K-pop groups commonly have dedicated fan clubs with a collective name and sometimes an assigned colour, to which they will release merchandise. For example, TVXQ fans are known as 'Cassiopeia', and their official colour is 'pearl red'. Some of the more popular groups have personalised light sticks for use at concerts; for example, Big Bang fans hold yellow crown-shaped light sticks.