Most customers prefer to pay in cash on delivery, and about a quarter of goods are rejected at the door.

ECONOMIST: Selling clothes online in Russia

For starters, Gavet says 80% of her customers pay for merchandise in cash on delivery.

FORBES: OZON.ru CEO Maelle Gavet: Running Russia's Amazon (VIDEO)

In response, he now asks some customers to pay upon delivery, using PayPal Here on his smartphone, which gives him an inflow of cash "in fractions of a second, " he says.

WSJ: Mobile Payments Brighten Small-Business Cash Flow