Prosperity is a comprehensive concept. A prosperous family has not only good economy, but also honor, good social network, happy family life, good health and clever children. A prosperous person probably is not rich, but must have a good living state and the living state is sustaibtable. There are many kinds of lucks. Fengshui which only favor one kind of lucks can already be called as good Fengshui. Fengshui which favor prosperity favor almost all kinds of lucks.
In the old days, people think Feng Shui of the tombs of his ancestors is the most decisive factor for the prosperity of man. However, the ideology can't be supported with present scientific knowledge. Therefore, seeking the most harmonic Yin Yang relationship in a Positive House (a house/apartment for alive people) is thought as the most correct method to get Feng Shui for prosperity.