Identical purchase requirements produced strikingly different outcomes depending on how a loyalty card was presented to customers. The distinction highlights a fundamental insight about human motivation: the way progress appears on paper can reshape whether people persist toward a goal.
In April 2004, researchers distributed 300 cards at a professional car wash, each promising one free wash after eight paid visits. One batch contained ten spaces with two stamps already filled in. The other batch had eight blank spaces. Over nine months, 34% of customers holding the pre-stamped card completed the offer, while only 19% of those with the empty card did so.
Joseph Nunes and Xavier Drèze documented this finding in their 2006 Journal of Consumer Research paper, naming it the endowed progress effect. The mechanism is straightforward: presenting a task as already underway increases the likelihood that people will finish it.
The starting line moved on paper
Both card variants required exactly eight purchases to earn the reward. The pre-stamped version showed 20% completion from the moment customers received it; the blank version showed zero. This 15-percentage-point gap in redemption rates emerged purely from how the progress was displayed.
The experiment's power lies in holding everything else constant. A lower price, reduced service cost or easier qualification requirement could each influence customer behavior for obvious economic reasons. By keeping the purchase requirement and reward identical, the researchers isolated presentation as the sole variable. This allows businesses to ask a sharper question: does showing the journey differently affect follow-through when the underlying deal is equivalent?
Related research found the finish line mattered
A parallel 2006 study by Ran Kivetz, Oleg Urminsky and Yuhuang Zheng explored the goal-gradient hypothesis in consumer contexts. Café loyalty program members purchased coffee more regularly as they drew closer to earning a free drink. When researchers compared a standard ten-stamp card against a twelve-stamp card with two bonus stamps included, customers given the apparent head start completed the ten required purchases more rapidly. Online song raters also showed increased participation as they neared a reward.
These findings address how perceived distance influences effort. While connected to the car-wash result, they represent distinct experiments with different activities and metrics. Faster completion and higher completion rates both matter for a rewards program, yet they measure different things. Someone might make a purchase sooner without generating an additional purchase overall. Participation might rise among existing members without attracting new ones. The measurement must align with what is being claimed.
Progress looks different early and late
Motivation researcher Ayelet Fishbach, in her Chicago Booth teaching material on progress monitoring, describes the small-area principle. Early in a bounded task, emphasizing completed actions can make the next step feel important. Later, emphasizing what little remains can serve the same function.
The logic rests on proportional impact. Advancing from one completed step to two doubles the visible accomplishment; reducing two remaining steps to one halves the visible distance. The same arithmetic permits different framings of an identical next action. This does not prescribe that every progress display switch at the halfway point, but rather suggests a design hypothesis worth testing in specific contexts. A newcomer deciding whether to continue and a veteran nearing a reward may respond to different information, even within a single program.
The experience between rewards still matters
Motivation toward a distant goal involves more than progress visualization alone. Research by Kaitlin Woolley and Fishbach, spanning five studies of activities including studying, exercise and eating vegetables, found that immediate rewards correlated more strongly with actual persistence than delayed rewards. Enjoying the activity itself along the way could matter even when a longer-term benefit motivated the original goal.
For a service business, this suggests evaluating each visit's quality alongside the final prize. This represents a design inference, not evidence that enjoyable car washes caused the loyalty-card effect. Different mechanisms may drive repeat behavior and warrant separate investigation.
Completion is useful evidence, but not the whole business
A company testing this approach should maintain simple qualification rules and compare equivalent offers fairly. Then it should monitor the outcomes that actually matter: completion rates, intervals between visits, total purchases, reward expenses and whether customers return after redeeming.
Each metric answers a different question. Redemption demonstrates that someone reached a threshold. Retention reveals what happened next. Profitability hinges on the costs and revenue tied to those actions. Success on the first measure does not resolve the other two.
The takeaway for practitioners: make the hypothesis specific and the comparison equitable. A visible head start is a testable offer feature, not a replacement for understanding why customers value the service. A loyalty card tracks progress; the business must still earn the next visit.
Source: Silicon Canals
