Impulse buying is spontaneous, ill-considered purchasing behaviour that is usually triggered by emotional factors and situational circumstances rather than careful analysis or planning. Often an impulse purchase is the acquisition of items that were not on the shopping list and may not even be needed. Impulse buying is a common phenomenon in many retail environments, both brick-and-mortar and e-commerce.

In marketing psychology and neuromarketing, impulse buying is intensively researched in order to understand which psychological and neurological mechanisms influence behaviour. Factors such as visual stimuli, product placement, price promotions and even music can increase the likelihood of an impulse purchase. Techniques that elicit emotional responses, such as the use of colours that create a positive mood or marketing messages that convey a sense of urgency, are particularly effective.

Another important aspect is the reduction of the cognitive load for the consumer. The simpler and more intuitive the purchase process is, the more likely an impulse purchase is. Online shops use one-click purchase options, for example, to minimise the inhibition threshold for a spontaneous purchase.

If companies understand the underlying mechanisms of impulse buying, they can develop targeted marketing strategies to promote this type of buying behaviour and thereby increase sales and profits.