Sezzle Inc., the Minneapolis fintech company that went public in Australia last month, on Friday reported six-month financial results that showed it is essentially still in startup mode — with rocket-like growth and huge losses.

Sezzle’s revenue of $4.3 million from January through June was more than 16 times greater than in the same period a year ago. But it lost considerably more money, too — $4.7 million compared with $1 million in the first half of 2017.

Underneath those financial figures, however, Sezzle disclosed operational metrics that showed the installment-payment system it provides online retailers is being rapidly embraced by those firms and their customers.

Sezzle offers an alternative to credit card payments for online shoppers who don’t have credit records or have poor ones. Retailers offer the Sezzle system as an option at checkout alongside credit cards and PayPal.

Consumers used the Sezzle payment method to make purchases on $28.3 million of goods in the first three months of the year and $42 million in goods during the second three months. Overall, that $70 million worth of transactions is about 20 times the volume of activity for the Sezzle payment system in the first six months of 2017.

“We’ve seen a strong increase in customer and merchant accounts in addition to our revenue growth,” Charlie Youakim, the company’s chief executive, said in a statement. “We believe that Sezzle is on the leading edge of an international installment-payments megatrend that has only begun to take shape.”

The company reported that it had 5,048 active merchants using its system at the end of June, up 52% from the end of March. It also said that at the end of June it had nearly 430,000 “active customers,” or those who have used the system at least once in the preceding 12 months, up 60% from the end of March.

Sezzle was formed in 2016 but pivoted its strategy to develop the installment-payment platform in 2017. Executives decided to list the firm in Australia because its biggest rivals are based there, installment-based payments are more common in that market and large investors have developed a record for understanding such businesses.

Sezzle shares, which debuted at A$1.22 on July 30 and climbed to A$2.20 on the first day of trading, closed down 1% at A$2.49 ($1.68 in U.S. dollars) on Friday.

It raised about $30 million from the stock offering and is using the proceeds to add staff and build up its marketing team to attract more retailers to offer its payment system.