The HAM - Hippocampus-Amygdala-Memory - effect refers to limbic structures involved in emotional memories. The Amygdala is responsible for stamping emotional significance to experiences. The Hippocampus is vital for encoding and recall of memories.
Aim to create strong sensory memories with every interaction your consumer has with your brand. Aromas impress the strongest emotional memories because the olfactory nerve is located right next to the limbic system – our emotional brain. Companies like ScentSational Technologies (http://scentsationaltechnologies.com/) know how powerful sensory stimulation is as a marketing tool. They offer aroma-releasing packaging for consumer products. With each interaction the consumer has with the package, emotional memories are triggered and a strong memory is developed around the product. So even if a potential customer does leave before purchasing, the HAM effect may draw them back.