Contemporary art galleries are often open to the general public without charge; however, some are semi-private. They profit by taking a portion of art sales; twenty-five to fifty per cent is typical. There are also many non-profit or collective galleries. Some galleries in cities like Tokyo charge the artists a flat rate per day, though this is considered distasteful in some international art markets. Galleries often hang solo shows. Curators often create group shows with a message about a certain theme, trend in art, or group of associated artists. Galleries sometimes choose to represent exclusive artists, giving them opportunities for regular shows.