The mobile app marketing industry is powered by several business models. From one-off payments to costs-per-metric, there is a number of models for mobile app marketers to choose from upon launching an app advertising campaign. CPI, or cost per install, is one of them, and while on the surface the name makes it sound deceptively simply pay-per-install means you pay when someone installs your application, there is actually plenty of nuance to it. App marketers are in a tough ever-increasing competition and so to meet their marketing goals, they may utilize all these models. Mobile apps flood the market today and they are developed for various functions, such as entertainment, food delivery, taxi service, photo editing, learning, language translation, communication, shopping, videos, games, music, news, weather, and a lot more.