Microtransactions are commonplace in many "free to play" smartphone titles, including Pokémon GO. However, the amazing success of Niantic's title has attracted the attention of Japan's Financial Services Agency, which is apparently considering regulation for the app's in-game currency, "PokéCoins".

According to the Financial Times, the Agency is considering classing PokéCoins - which are purchased with real money and are used to buy items in-game - as a form of prepayment.

The talks between the Agency and Niantic are still ongoing, but if the regulation did come to pass it would mean that the Pokémon GO developer would have to disclose the balance of unused PokéCoins held by users in March and September of each year. If in either month the total number of PokéCoins came to more than 10 million Yen (approximately $96,442), then Niantic would have to deposit up to 50 percent of the unused currency balance in a Japanese bank account as "security".

If this did come to pass, then it would have massive ramifications for the entire "free to play" smartphone sector. Pokémon GO is certainly very successful when it comes to in-app purchases, but it's by no means the only game to use this system - nor is it the first.