Strong sales of books, music and electronic devices helped online retailer Amazon more than triple its profits in the three months to June.
Third-party vendors selling through Amazon is key to the firm
Profits grew to $78m (£37.8m) on sales which were up 35% to $2.88bn - better than analysts had predicted.
It added that the volume of items which were sold through its site by third-party vendors had increased to 30% of total unit sales.
Amazon shares soared by 11.3% in after-hours trading.
The firm added that there had been an increase in the number of people who had signed up to the free postage scheme it offers to its US customers.
Providing unlimited postage for a one-off fee of $79 a year, the offer eats into Amazon's bottom line but is seen as a long-term strategy.
Globally, the company took more than two million pre-orders for the final Harry Potter book, although is selling the JK Rowling tome at a hefty discount.
It has also announced plans to launch a digital music store that will allow customers to download music without any digital copyright protection.