"[The] attitude transfer process may be more complex than suggested by current models," write Huifang Mao and H. Shanker Krishnan. "For a multi-product brand, multiple referent points exist to judge a brand extension, resulting in more complex evaluative processes."
For multi-product brands, the researchers distinguish between the two measures consumers use to decide what they think of a newly released product: brand fit and product fit. "Brand fit" is the degree to which a new product is consistent with the overall brand image, and knee pads would fit well with the athletic Nike persona. However, certain new products that do not mesh with the Nike brand might still garner a positive consumer reaction if they demonstrate "product fit." A Nike car audio system, for example, would have high product fit with Nike's existing line of audio equipment for joggers. Surprisingly, this second type of association is often easier for consumers to make, the researchers found. "Consumers tend to transfer attitudes from varying sources to a brand extension," explain the authors. "[But] consumers may transfer their liking for an existing product to an extension in a spontaneous fashion."
Huifang Mao and H. Shanker Krishnan. "Effects of Prototype and Exemplar Fit on Brand Extension Evaluations: A Two-Process Contingency Model" Journal of Consumer Research. June 2006.
Journal of Consumer Research