The performance of agglomerated products is determined by their composition, structure and the process used to form them. Some theoretical concepts that may be useful in the design of agglomerated powder products are discussed. They allow estimation of important properties of agglomerated products, such as the bulk density, the strength of wet and dry granules and the kinetics of liquid wetting. To illustrate the application of these concepts, a description is given of the manipulation of the structure and performance of detergent, fine chemical and food granular products. It is argued that the concepts are also useful in the selection of the granulation process and its manipulation to achieve desired product properties.