From New Scientist‘s Feedback column:
HAVE you wondered why manufacturers have taken to adding scents to more and more consumer products – including car tyres (28 March 2009)? If so, a study in the US Journal of Consumer Research, has this answer: “Product scent may be particularly effective at enhancing memory for product information as a function of its ability to enhance a product’s distinctiveness within its surrounding context.”
Shorn of its clunky language, what this means is that if products have a smell you’re likely to remember them better. That makes sense to us. We always make a point of remembering which products are scented so we’ll be sure never to buy them again.