Despite the growing need for marketers in luxury retail to provide memorable customer experiences via their retail outlets, research investigating the effectiveness of experiential stores on brand and behavioral outcomes is scarce. To address this gap, we investigate the effectiveness of pop up brand stores, which we define as temporary stores that are open for a limited period of time, representing an increasingly popular experiential store format in the luxury fashion and automotive industry. However, pop up brand stores not only reflect one of the latest developments in experiential retailing, but they are also seen as an effective marketing tool to reach new target groups which might perceive traditional luxury as antiquated or obsolete. Collecting data from 345 visitors of two pop up brand stores of a luxury car brand in the US and the UK, we find that three store characteristics – hedonic shopping value, store uniqueness, and store atmosphere – either directly or through brand experience exert a positive effect on word of mouth (WOM) intentions towards the brand. Whereas hedonic shopping value and store atmosphere strengthen the customer’s experience with the luxury brand, store uniqueness, surprisingly, does not. Using brand familiarity as a moderating variable, we further unveil that pop up brand stores create positive WOM in both existing and new target groups. Our empirical results offer novel insights for researchers and marketers, as we quantify the effects of experiential store characteristics on brand experience and WOM, shed light on the role of brand experience in inducing behavioral intentions, as well as illustrate that pop up brand stores are an exceptional opportunity for luxury brands to reach existing and new target groups alike. We argue that pop up brand stores should thoughtfully be considered as a complement to traditional luxury retail and as an alternative to flagship stores.