Viva Republica, the operator of Toss, said its facial-recognition payment service FacePay has doubled in size in three months.

Toss said on Monday the cumulative number of FacePay subscribers has exceeded 6 million. It reached 3 million in February, just three months earlier.

FacePay topped 4 million subscribers in March and 5 million in April before surpassing 6 million in May. That means 3 million new subscribers joined in about three months after it passed 3 million in February.

A simple calculation suggests about 1 person signed up every 2.7 seconds. It took 23 days to climb from 5 million to 6 million.

Actual use is also increasing. Of users who have made at least 1 payment, 60 percent repeatedly used FacePay as a payment method. The most active customer has made more than 2,000 payments in total using FacePay.

Its places of use are also expanding. As of early June, the cumulative number of affiliated merchants with Toss Front terminals that can accept FacePay payments has exceeded 370,000. Toss Front is distributed across all 226 cities, counties and districts nationwide.

Industries adopting the service are also expanding from everyday businesses such as cafes, restaurants and convenience stores to a range of offline locations including bookstores, highway rest areas and auto repair shops.

Toss explained that the expansion of places of use and improvements to the user experience have led to subscriber growth.

A Toss official said, "FacePay's subscriber growth shows that facial payments are becoming established as an everyday payment method," adding, "We will continue to develop our technology and services so that more users can naturally experience facial payments."