Dictionary.net

The distinction between a good and a valuable consideration is that the former consists of blood, or of natural love and affection; as when a man grants an estate to a near rela- tion from motives of generosity, prudence, and natural duty; and the latter consists of such a consideration as money, marriage which is to follow, or the like, which the law esteems an equivalent given for the grant 2 Bl. Comm. 297. A valuable consideration is a thing of value parted with, or a new obligation assumed, at the time of obtaining a thing, which is a substantial compensation for that which is obtained thereby. It is also called simply "value." Civ. Code Dak.