Modern tall buildings are often slender, lightweight, and possess low inherent damping, which can lead to excessive wind-induced motion. Dynamic vibration absorbers (DVAs) in the form of tuned mass dampers (TMDs) and tuned sloshing dampers (TSDs) are being commonly employed to increase the effective damping of structures, thereby reducing their resonant responses under wind excitation. While the performance of structure-DVA systems has been studied extensively theoretically as well as experimentally (at scale-model) in the laboratory, very few studies have reported on the as-built performance of real-world implementations. The performance of a DVA is typically quantified using the concept of �effective damping�. Until recently, it has been difficult to measure the effective damping of a structure, since the coupled structure-DVA system is excited through unknown, ambient excitation. In this study, a method is presented that enables the inherent structural damping (that is, the damping of the structure without the DVA), as well as the added effective damping (the damping that the DVA appears to add to the structure) to be estimated from full-scale ambient measurements of a structure-DVA system. The method requires the DVA and the structural generalized masses to be known and the structural and DVA responses to be measured. With this information, the motion reduction achieved by the implementation of the DVA is estimated. After the method is briefly presented, the remainder of the paper focuses on real life applications where the efficacy of DVAs implemented in full-scale tall buildings is presented.