#1183 2006 · Joseph Nunes & Xavier Drèze (car wash loyalty card field experiment) · Consumer psychology / loyalty marketing
Researchers pre-stamped two boxes on a loyalty card and completion rates nearly doubled
问题
Customers given a blank loyalty punch card requiring 8 purchases for a reward mostly never finished it
背景
Loyalty punch cards were everywhere — buy eight car washes, get the ninth free — but completion rates were quietly dismal: most cards were lost, forgotten, or abandoned a few stamps in, because eight blank boxes in a row look like a long, undifferentiated slog with no sense of how far along the customer already is. Marketing researchers Joseph Nunes and Xavier Drèze suspected the problem wasn't the number of purchases required, but how the starting line was framed.
They ran a field experiment at a car wash, handing customers one of two loyalty cards. Both required the same actual number of future purchases to earn a free wash. The only difference was the card's face: one showed eight empty boxes to fill; the other showed ten boxes, with two of them already stamped.
换别人会怎么做
The standard fixes for low redemption were to shrink the requirement (fewer purchases needed) or sweeten the prize, both of which cost the business real margin on every redemption. Nunes and Drèze tested whether the same economics, just reframed, could move behavior without giving up anything of value.
他们看到了什么
People do not judge a task by the distance remaining — they judge it relative to a movable starting point. A card with ink on it already says mid-project, not begin, though the math is identical.
那一手
The two-stamp head start was entirely artificial — both groups had to buy exactly eight more car washes to earn the free one. But the ten-box card with two pre-filled stamps reframed the task from 'start collecting' to 'you're already 20% of the way there,' converting an identical amount of remaining effort into visible, banked progress.
为什么管用
Because both groups faced the exact same eight remaining purchases, the effect isolates the psychological framing of progress from its substance. That starting point turns out to be manipulable without changing the actual finish line: a card that already has ink on it doesn't say 'begin a long project,' it says 'you're mid-project, don't stop now.' The pre-stamped card exploits loss aversion in reverse: abandoning a card with two stamps already on it feels like forfeiting progress already made, whereas abandoning a blank card feels like simply not starting a project you never really committed to. The company spends two cents of ink instead of one free car wash's worth of discount, yet gets a bigger behavioral response than a real discount typically produces.
值了多少
34% completed the pre-stamped ten-box card vs. 19% for the blank eight-box card — an 80% lift from two stamps of ink.
什么时候会失灵
The head start has to be visibly and specifically tied to the same goal — a generic 'welcome bonus' unconnected to the task's own progress bar doesn't produce the effect. It also erodes if customers become sophisticated enough to recognize the head start as arbitrary marketing rather than earned progress, and it can't manufacture motivation for a reward nobody wants in the first place; it only removes friction from a goal already worth pursuing.
后来呢
Nunes and Drèze published the finding as the 'endowed progress effect' in the Journal of Consumer Research in 2006, and it became a standard tool in loyalty-program and habit-app design — from coffee cards issued with a stamp already on them to fitness apps that show a progress bar starting above zero — wherever a company wants to convert a long blank task into a race already underway.
资料来源
- [1]The Endowed Progress Effect: How Artificial Advancement Increases EffortJournal of Consumer Research, 2006doi.org
- [2]Loyalty Psychology Series: Endowed Progress EffectLoyalty & Reward Co., 2021loyaltyrewardco.com