The huge success of Pokémon Go mobile game is expected to add $3bn to Apple's revenue over the next two years.

The mobile game’s 21 million players are buying PokéCoins from Apple app store, with the iPhone maker charging a fee to host apps on its App Store and sharing the generated revenues.

Pokémon Go has already raised Apple's market capitalisation by $2bn since its launch on 6 July.

Brokerage firm Needham estimates that Apple could see additional high-margin revenue from the game nearing $3bn in the next two years.

Needham & Co brokerage analyst Laura Martin wrote in a client note, “We believe Apple keeps 30% of Pokémon Go’s revenue spent on iOS devices, suggesting upside to earnings.”

Apple made $2bn in the first two years of availability for Activision Blizzard’s Candy Crush Saga mobile games.

Pokemon Go is a joint venture of the Pokemon Company, which is 40% owned by Nintendo, and Niantic, a spinout from Alphabet.

The free-to-play location-based augmented reality mobile game is available in 35 countries, including Canada and most parts of Europe. It is slated to launch in Japan this week.

Pokemon Go, which is also available on Android devices, had 21 million active users in the US alone as of 18 July.

App analytics company Sensor Tower noted that users in the US are spending more time playing the game than they are using Facebook or WhatsApp.