4.9 Goal Gradient Hypothesis
How close you are to achieve a bonus with your loyalty card, the more motivated you are. Compared to beginner coffee buyers, customers who almost complete a card buy more coffee (come back to the store sooner) (Kivetz, Urminsky, and Zheng 2006)
Similar effects are also found in animals, rats are more motivated when they are closer to their goals (Brown 1948; Hull 1932, 1934)
However, too far behind couples with direct competition could not only lead people a little behind more motivated, but people far behind more demotivated. (Fershtman and Gneezy 2011)
Interestingly, the mechanism for favored candidate to lose motivation is different from underdogs. To save face, favored candidate stops trying to have reason to excuse that if they were to keep trying, they would have won (Dai et al. 2018)