A person should practice Dharma, Artha and Kama. These three practices harmonize together as a person grows, from childhood to old age. In youth, a person best learns by Kama, in middle age by Artha, in old age by Dharma - and by using Kama to understand Artha, and Artha to understand Dharma, gains Moksha, freedom from distress, wisdom, enlightenment, perfection and satisfaction.
However, no one knows just how long they will live, and it is uncertain if a person will live to old age, or even to middle age. Thus, a person should use these three means (Dharma, Artha and Kama) their entire lives as a devoted student.
Dharma is best learned by obedience to duty, the performance of sacrifices - it is learned from study, and learning from those who are conversant in it. Artha is best learned by acquisition of wealth, the protection of that wealth - and the increase of that wealth. Artha should be learned from those versed in the means of commerce and industry, and especially from the King and his officers. Kama is best learned by enjoyment, the pleasure of the senses: hearing, feeling, seeing, tasting and smelling - as assisted by the mind and heart. By doing so, a person consciously understands the nature of pleasure. Kama is best learned by study, and practice.
Thus, the Dharma of Kama is Artha. The only exception to this is when Artha is identical to Kama: prostitution is both a business, and an act of pleasure: as is entertaining, sporting, cuisine, tourism - and various other acts of industry and commerce which trade in pleasure.