I've recently been having a look at this as my partner starts using Poshmark to sell clothing online. I haven't used it yet, but there are apparently several ways to use the app to make your items more visible to the community. I hope to have a closer look at the app next week. Some offhand thoughts on in-app scarcity for something like Poshmark: The scarcity in is real - limited user attention and the desire to have your items seen by more people are competing with each other. Designing in-app mechanisms to help surface items is a logical next step. And being that these things are tied to actual income in Poshmark, I think it might muddle up some of the clear ethical lines. Imagine making a blanket statement about reducing the number of notifications in the Uber app for drivers. Being that money is now programmable, I imagine that only more of our ethics and economics will seem at odds within increasingly personal contexts.