Booking.com, a popular site for finding accommodation, frequently shows users when hotel rooms have sold out or shortly will. Scarcity of availability encourages and persuades visitors of the site to make a quick decision to book, rather than waiting and potentially missing out. Making an alternative appear scarce or rare increases its perceived value. In this case, if hotel rooms on booking.com appear to be selling fast in comparison to other sites, it heightens the sense of urgency to book. To add to the sense of scarcity the number of hotels found along with the number that are currently available is made clear to the user. This emphasises the popularity of their search, as well as highlighting the shortage of remaining hotels. The failure to possess or obtain a scarce object can create frustration and imply that the self is lacking in some regard. In contrast, possessing a rare item may result in increased feelings of uniqueness and self-worth
Worchel, Lee and Adewole (1975) provide evidence for this scarcity effect that booking.com have deployed. In the study, 200 female undergraduates rated the value and attractiveness of cookies that were either in abundant supply or scarce supply. In the scarce condition, the cookies were either constantly scarce or they began in abundant supply and then decreased. Subjects were told that this decrease in supply was either due to an accident or to a high demand for the cookies. In the abundant condition, the cookies were either constantly abundant or first scarce and then abundant. The increase in supply was either due to an accident or to a lack of demand for the cookies.
The results, shown in table 1, indicate that cookies in scarce supply were rated as more desirable than cookies in abundant supply. Furthermore, cookies were rated as more valuable when their supply changed from abundant to scarce than when they were constantly scarce. Additionally, cookies scarce because of high demand were rated higher than cookies that were scarce because of an accident. This study illustrates the ability of scarcity to create a sense of urgency and panic that increases its effectiveness as an influence device
Worchel, S., Lee, J., & Adewole, A. (1975). Effects of supply and demand on ratings of object value. Journal of Personality and Social Psychology, 32, 906-914.