This paper documents the application of prior knowledge about response patterns in brand image data for private label (PL) brands. We investigate if a well‐known pattern about response level and usage experience also holds for PLs. The main finding is that advertised national brands (NBs) enjoy a higher level of knowledge amongst their non‐users than do PLs. We did not find this to be the case for small non‐advertised NBs and small PLs. The finding emphasises the importance of advertising for NBs to maintain their position. Well‐branded and appropriately scheduled advertising leads to building up brand associations in consumers' memory, which increases the probability of thinking about or noticing a brand. We suggest that the higher knowledge among NB non‐users is the main advantage NBs have over PLs in the market. We provide implications of the findings for managers and academia. Copyright © 2014 John Wiley & Sons, Ltd.