The Endowed Progress Effect
When people have made progress towards a goal they will become more committed to continuing and achieving that goal. The endowed progress effect describes the behavior where, if progress is artificially created (for example by giving someone a head start), people still become more committed just as if they had created that progress themselves.
Researchers Joseph C. Nunes and Xavier Dreze tested this idea with loyalty cards for a car wash when they came up with it.
They handed out cards requiring 8 purchases for a free car wash, which means the customers had to get 8 stamps to redeem the reward. They also handed out cards requiring 10 purchases but with two of the spaces on the card already stamped. Each group technically needed to put forth the same amount of effort to get their free car wash.
After 9 months, 34% of the people with 2 free stamps had redeemed their cards versus 19% percent who had cards without stamps.
- Nunes, Joseph & Drze, Xavier. (2006). The Endowed Progress Effect: How Artificial Advancement Increases Effort. Journal of Consumer Research. 32. 504-512. 10.1086/500480.