Attribute it to Swedish mistrust of credit cards and internet commerce, combined with the Nordics’ rapid adoption of mobile whose small screens do not make entering credit card details easy.

Swedish shoppers didn’t like using their credit cards online, and they wanted to see that a store sent the right color and proper size before they paid. So Klarna let them buy and choose to pay in 14 days; all they need to do is enter their name, birthday and address. Of course it helped that in Sweden that was enough information to get a person’s income and so Klarna could run risk assessment. The company pays the merchant immediately, regardless of how the sale goes, and then collects from the buyer. The buyer can decide to pay with a credit card, direct bank transfer or use credit from Klarna. which lets buyers pay over 6 to 12 months.

Now it is expanding into the U.S.

“Klarna increases the average order value by 30% to 60%, said Stefan Weitz, Chief Product and Strategy Officer at Radial which provides its own payment guarantees and also offers comprehensive warehouse and shipping services for internet commerce.

“Consumers will buy more if they can pay over time.”

Small and mid-size merchants and let Klarna handle their whole checkout experience, something attractive to apparel and shoe sellers who are getting hit with chargebacks For a large enterprise which wants a fully customized site and has chargebacks under control Klarna can offer its delayed payments service — Try before you Buy, said Brian Billingsley, Klarna’s CEO for North America.

“We let consumers, after they have entered their shipping details, buy and have it shipped before they have to give any payment credentials.” That has great attraction for fashion, shoes and apparel where shoppers often buy more than one of an item, try it on and send back what they don’t want. It’s also popular with debit card users because the money doesn’t come out of their account until they decide what to buy; they don’t have to wait days for a refund after they return some items.

The company uses behavioral tools, geolocation, data, time of day and even keystrokes to decide what to offer buyers while making it as simple as possible for them.

With the user’s email and zip code it can quickly determine if it has seen the buyer on another shopping site and pre-fill her information and show what options are available. Entries that are typed in all letters raise or are entered at 3 a.m. may indicated higher risk, said Klarna co-founder Niklas Adalberth in an interview printed in Chris Skinner’s recent book Value Web. Someone ordering Champagne is a better risk than someone buying beer, he added.

Billingsley said Klarna has kept U.S. losses lower than the company’s plan as it builds up customer data and its risk experience.

“In Sweden or Germany we leverage our own credit bureaus. In the Nordics we have seen almost every consumer of legal age, so we are quite confident in our own data sets. In Sweden we see about 70% of the people who shop online we can identify so they don’t have to enter bill, ship-to or payment data. We make it almost Amazon [at any store].”

Credit data is very specific by market, he added, and the company collects SKU level data on every transaction.

“An iPad will be high risk in any market; some shoe brands are higher risk than others.”

Each market has its own rules on data, data privacy, know your customer (KYC) and in the U.S. on multiple types of discrimination.

“Merchants come to us and we can issue credit in nine markets; no one else can do that,” he explained. “We comply with each market. Our merchants who leverage that most are global merchants, where U.S. companies are selling to Europe or Asia, or Asians selling to the U.S., they can take advantage of us and use credit or local payment methods.”

It used to be that merchants had to achieve a certain size before they tackled cross-border sales, but no longer.

“Now they expect that as soon as they get a web site they should be able to sell to the world. No  merchant in the UK that doesn’t sell to surrounding countries.. In ecommerce, you have to sell globally to be competitive. Only a few things are holding small firms back — customs, tax and shipping, and there are companies that can help with those.

Klarna has seen merchants sharply increase their percentage of completed sales, rather than abandoned shopping baskets, he said. The desktop payment experience is not a good fit for mobile.

“You have to type so many fields with your thumbs.”