User Acquisition (UA) refers to the process of acquiring new users or customers for a product or service. Since no game can pin its growth purely on ‘going viral’, spending money to attract new users and getting them to install or engage with the game is a key element for success. Modelling user acquisition is critical to forecasting the success of any the game, but in particular it is important to be able to analyse the potential impact of increasing or decreasing spend in a giving segment or region.