Many stages have actual railing built on or around the stage to function as the tip railing, in addition to indicating where customers should position themselves relative to the performance zone. Customers take turns tipping the dancer. They may also line up to tip popular performers. If physical railing is not present, the tip rail is the edge of stage or defined performance area. Other common tip methods are to insert the dollar into the stripper's cleavage from the hand or mouth, to simply place it or toss it on stage, or to crumple bills into a ball shape and throw them in the entertainer's direction. Each club and dancer has different tolerance levels for customer interaction, including tipping. Some clubs have multiple stages on the premises. Tipping etiquette varies between countries and cultures. In Eastern European and Asian clubs it is customary to agree on payment upfront for a certain amount of time or dances, for stage performances and any private sessions.