From a Cornell Economics paper:

Sex workers in Geylang are located on the even numbered lorong (lanes). Each lorong is controlled by a pimp who oversees the business, protects the women from abnormal clients and arrest in the event of a police raid, and provides accommodation. Tourist visas enable sex workers to re-enter Singapore frequently. When a sex worker travels to Singapore, the costs are usually borne by the parties who manage her trip and work. In return, she provides the first 60 services for free and pays S$10/day and 30-40 percent of her subsequent earnings to the pimp.

The service rate ranges from S$27 to S$250 with a median of S$60 and mean of S$70. Over 92 percent of sexual services took place in motels and hotels, with the remainder primarily at the client’s residence. A full-time sex worker will return to her original venue immediately after finishing with a client. Any costs, such as taxi fare and hotel room charges are usually borne by clients.