This paper focuses on a specific strategy that developers of mobile applications may use to stimulate demand: The release of updates. We develop a theoretical analysis that shows that developers have incentives to release updates when experiencing a drop in performance. The predictions of the model are then tested using an unbalanced panel of top 1,000 apps in iTunes and Google Play for five European countries. We estimate that while in iTunes the release of an update stimulates a 26% increase in download growth, in Google Play updates play a less significant role. This difference is partly due to systematic differences in apps and in developers operating in the two stores (“selection effect”), and partly to a lack of quality control on apps and updates in Google Play (“quality check effect”). These findings highlight the crucial importance of an appropriate management of updates as well as the relevance of institutional characteristics of the app stores.