The emerging field of game user research (GUR) investigates interaction between players and games and the surrounding context of play. Game user researchers have explored methods from, for example, human-computer interaction, psychology, interaction design, media studies, and the social sciences. They've extended and modified these methods for different types of digital games, such as social games, casual games, and serious games. This article focuses on quantitative analytics of in-game behavioral user data and its emergent use by the GUR community. The article outlines open problems emerging from several GUR workshops. In addition, a case study of a current collaboration between researchers and a game company demonstrates game analytics' use and benefits.