Boozt and other Nordic retailers are, however, bracing for a pick-up in competition after U.S. e-commerce giant Amazon.com said earlier this month it was preparing to launch a Swedish site, confirming long-running rumours.

Boozt said second-quarter sales rose 38% from a year earlier to 1.22 billion Swedish crowns ($140.2 million) as its core platform Boozt.com grew 29% and cut-price Booztlet.com - on which the group has said it is increasing focus - jumped 168%.

Operating profit leapt 146%, to 120 million crowns.

"The migration from offline to online has accelerated and we have worked hard to strengthen our market position," CEO Hermann Haraldsson said.

"We welcomed more than 300,000 new Nordic customers to our platforms during the second quarter and they, as well as our returning customers, have increasingly shopped in our adjacent categories to fashion, such as kids, sport, and beauty. Men also increased its share of revenue," he said.

Boozt's shares were up 7% in early trade, taking their year-to-date rise to 116%.

Physical stores in the Nordic countries have largely not been forced to shut down during the pandemic, but other government restrictions and wariness among consumers have reduced footfall to varying extents.

Boozt, which does around 95% of business in the Nordics, forecast a full-year operating margin of 3.5-4.5%. In June it had forecast a margin of 3-4% on sales growth of 20-25%, a sharp increase on its previous projections.

(Reporting by Anna Ringstrom; Editing by Mark Potter)