Does size matter in fit perceptions, extension evaluation and post-extension brand image?

There has been extensive research on brand extensions, but no previous study has directly compared how consumers evaluate the extensions of competing brands within a product category and no previous research has considered the potential effect of brand 'size‘ or market share on post-extension brand image and on consumer brand extension evaluations. Yet, empirical evidence over the past forty years has consistently shown a strong correlation between attitudinal responses to a brand and the number of its buyers (or its market share). This study compares consumers‘ evaluations of the brand extensions of competing brands within a product category (pet food) and explores whether the correlation between attitudinal responses to a brand and the number of its buyers described in previous research on attitudinal responses (e.g. Castleberry & Ehrenberg, 1990) does occur in the context of fit perceptions and of extension attitudes. Results reveal a positive correlation between brand 'size‘ (in terms of the number of brand buyers) with pre- and post-extension brand image and also with extension evaluation and fit perceptions. The same results apply to both high and low fit extensions.