Products in fast moving consumer goods categories come as different variants such as pack-sizes, pack-types, flavours, forms, formulae, etc. These variants are functionally highly differentiated from each other, often each based on a specific attribute. This research study empirically examined whether these functional differences affect customer loyalty for the variants of products. A number of market performance measures were used to assess the impact of market shares size on levels of loyalty. This book is useful tool for understanding a robust method of examining patterns of loyalty in consumer markets. The findings here have conceptual and practical significance, giving insights into a so far largely unknown aspect of consumer behaviour. This knowledge should help business managers develop a better understanding of marketing management-related issues such as product, line and brand management, assessing competitive tactics, setting targets for new brands, and impact of promotion and other marketing mix factors on the growth of brands. The book should also help consumer researchers as it reveals several future research directions.