One of the key uses of scarcity online is the use of a “limited number” of items available. While this may or may not be true, if there is a perception that you might miss out on something it becomes much more valuable and you are more likely to acquire said object.
Many sites that sell either products or services have recently started displaying X number still available or X items left in their product messaging.
Threadless, an online T-Shirt Retailer displays “X Left” once a T-shirts stock volumes becomes low.
This pushes people to purchase more quickly, before Threadless runs out of your size.
Orbitz uses Scarcity to try and persuade consumers to “Act Fast – Only X number left”
Below is how Travelocity highlights the “X number left”.
The practice of exposing low quantities of a product on e-commerce sites is a very powerful element of the Scarcity principle, which feeds into the consumer’s psychological need to compete with others for an item, which in turn makes that item more attractive to them.