Given a group action on a set of combinatorial objects, a statistic on these objects is called homomesic if its average value is the same across all orbits. The notion was coined in 2015 by Propp and Roby, who were motivated by earlier examples of this phenomenon from chip-firing on graphs (2008) and rowmotion on antichains (2009). In this talk, we will present a family of posets whose number of inversions are homomesic with respect to the promotion action.