Mobile game whales are a tiny group of users (around 1-2%) that drive the most revenue for mobile apps and game publishers. In most top-grossing games, the whales represent the smallest percentage of users who are responsible for up to 50% or more in revenue sales of an app. In the last three years, the percentage of paying players per game in North America has increased by a third (to 4.02%), and by a fifth (to 2.43%) in Europe (Delta DNA)