Marketing research has long recognized the relevance of consumption vocabulary to consumers' individual perception and preference formation. Little research, however, has investigated how such vocabulary might guide interpersonal product discussions and, hence, the diffusion of information. This paper reports a longitudinal field experiment in which we arranged 40 online discussion groups about a concept car that each lasted three weeks. We show that providing a specific vocabulary for certain product features encourages communication about those features, yet lessens communication about other product aspects during discussions. Consequently, the vocabulary also affects which product features are recalled after discussions. Our results support the notion that these effects of vocabulary are not consciously reflected upon and arise mainly from consumers' increased ability to verbally refer to features as opposed to increased feature salience.