the show and services. The Block in Baltimore, Maryland, has aggressive doormen stationed at nearly every entrance, only feet apart in a highly concentrated area of clubs. Broadway in San Francisco, California, has fewer clubs clustered together, but practices similar activities with their doormen. Waitstaff are also employed to assist with providing drinks, and in some cases meals, to customers on the main floor and others areas of the club. Shooter girls are specialized waitstaff that carry pre-prepared drinks in shot glasses, that customers can conveniently purchase. Depending on the local ordinances, these shots may involve some erotic part of the body of the shooter girl, typically her cleavage, in the delivery. If a club has a policy of setting a drink minimum per visit or per hour, the floor staff also assists in enforcing those rules. Dancers may also be required to generate a certain number of drink purchases per shift and as part of their rounds, the waitstaff may ask customers if they would like to buy a drink for the dancer seated with them. If a kitchen is present and if premium fare is offered, the club may also employ a chef to prepare and cook food items. Parking lot attendants can include people who simply coordinate where to park and how much to pay or they may also include formal valets, who will park a vehicle and keep track of the driver's keys while he or she is in the club. Some clubs require paid or valet parking to be used if keeping cars on the premises, to generate revenue and help regulate patron behavior. Bathroom attendants monitor the restrooms on behalf of management; primarily watching for policy violations and potential liability concerns. In strip clubs, policy enforcement can range from watching for drug use, sex, fighting, and other activities the club would prefer to see done off the premises. The attendant will also attempt to keep the restroom area clean, assist with the washing of hands, and if available, provide by request an assortment of cologne, mints, and other disposable items. Business and operations As a global industry, strip clubs are booming. As of 2009, there were between 3,500 and 4,000 strip clubs in the United States alone. More money is spent in the U.S. in strip clubs than is spent on theater, opera, ballet, jazz and classical music concerts combined. Some clubs have hundreds