FN400 effects bear directly on the interplay of conceptual fluency and buying. FN400 has been discussed as an index of familiarity (Rugg et al., 1998) or conceptual priming (Voss & Paller, 2007). Our results are consistent with the idea that FN400 is indicative of conceptual processing. FN400 increased with buys under promotions for High MA (and Low MA), but with non-buys under no promotions. We take this to mean that to the extent that consumers are able to activate a semantic processing subroutine for price promotions this is inferred as beneficial and increases purchasing. Possibly this reflects an initial attempt at identifying the post promotion price. In contrast, High MA consumers may form naïve theories that ease of evaluating a non-promoted price equates to a good price