Newton's first law of physics states that there is an inertial quality to bodies: those in motion tend to remain so, while those at rest do so too, unless there are external forces. Is it possible that humans exhibit some version of this? Habits are one example, with bad ones being hard to stop and good ones hard to start (at least for me). Researchers have recently shown that there is a shopping momentum effect too, whereby a consumer can't help buying more once an initial purchase has been made. This does not relate to consolidated buying (saving time by buying many items on one trip) or complementary buying (going in to buy a suit and buying shirts and ties to match). Shopping momentum is when an initial purchase (driver product) triggers additional purchases (target items) that otherwise would not have been made.
Previous research in psychology has proposed two mindsets that people possess: deliberative and implementation. In the deliberative mindset a person, well, deliberates. Pros and cons of a situation are evaluated. On the other hand, an implementation mindset helps focus on the timing and sequence of action. Importantly, switching from one mindset to another can change a person's thoughts and behavior. Hence while thinking about a (first) purchase a person can be in a deliberative mindset, but once a purchase has been made an implementation mindset comes into play. This facilitates further purchases with less deliberation and more action orientation. Anyway, that is the theory and to test it the researchers conducted a few experiments.
The first experiment was quite straightforward. Participants were given an unrelated task and paid for it. Those in the control condition were given the chance to buy the target product with that money. People in the test conditions were first given the chance to buy a driver product followed by the target product. The idea is that purchase of the driver product should increase the likelihood of purchase of the target product. This is exactly what happens, showing that the purchase of the driver product influences the target product purchase. In subsequent experiments, the authors confirmed that the critical idea is the shift of the mindset from deliberative to implementation. Even when later purchases are not involved, people generate more implementation thoughts when they have purchased a driver product compared to a control group. In other words, participants who buy the first product seem unable to stop themselves from getting into a shopping mode.
Okay, but does this mindset shift need an actual purchase to trigger it? Curiously, the answer is no. Another experiment revealed that simply putting people in an implementation mindset was enough to make them more likely to purchase a product. That is, just thinking about the steps needed to buy a product makes them more likely to buy a subsequent product!
But how strong is the shopping momentum effect? It appears to be strong enough to produce significant effects in the short term, but it also appears to be easily disrupted. The researchers were able to interfere with it quite easily by introducing extraneous situations such as devaluing the driver product by steeply discounting it. I mentioned in a previous post on marketing placebos , the strong negative impact that discounts have on people. Here is another situation where steep discounts appear to work counter to what a marketer would want to happen. The authors suggest the alternative of featuring a hard to get product at the same discount as other products in the store, rather than a steep discount on just one product.
These are all short term experiments. It is unknown what the long term impacts are. Does repeated uninterrupted deployment of the implementation mindset subsequently make it easier for a person to shift into this mindset? Are there certain types of people who are more susceptible to this mindset? It would appear so, given the number of people who seem to exhibit it in real life. Would people's tendency to be a tightwad or spendthrift affect their mindset shift? How conscious are people of this effect and can they stop it if they are aware o fit? These and other momentous questions remain open at this time.
This research was conducted by Ravi Dhar the George Rogers Clark Professor of Marketing at Yale, Joel Huber, the Alan Schwartz Professor of Marketing at Duke and Uzma Khan, Assistant Professor of Marketing at Stanford. It appeared in the Journal of Marketing Research.