This case provides a post-mortem of the advertising technology (adtech) company Sizmek. Sizmek grew via multiple acquisitions, with the vision of becoming an integrated adtech company that could leverage AI to buy digital media, while creating and serving display and video content. At its peak, one of its acquisitions had an IPO valuation of almost 1 billion dollars. However, Sizmek struggled with an integration that was taking longer than expected, but also with misalignment of agency incentives, stricter data privacy regulations, and the rise of the walled gardens - Google, Facebook, and Amazon - that made the adtech ecosystem very competitive, with dynamics of winners-take-all markets. By 2019 Sizmek had to file Chapter 11, and was sold in pieces. Is there anything Sizmek could have done differently in their go-to-market strategy, product road-map, or overall partnerships to avoid such rapid collapse?