After the business rooms are available, begin hiring people to bring you more profit. Try to unlock all three rooms as soon as possible. However, do not fill them with cheap and lazy workers. Each worker category has different jobs available. The more expensive a worker is, the better he or she will perform. If you do not have money or are saving it, hire all the workers possible and send them to work. You fire them later. Only fire workers if you can replace him or her with a higher value one that will earn more. Upgrade your building and purchase more floors.