Online retail giant Amazon did the unimaginable in June, reaching one out of every five Internet users, tracking firm comScore said Wednesday.

Amazon.com sites had 282.2 million visitors during the month of June, or 20.4 percent of the worldwide Internet population, reported comScore in a report on the top global retail and auction sites.

Ebay, the online auction site, received 223.5 million visitors in June, or 16.2 percent of the total number of Internet users, according to comScore.

"Technology has changed the way consumers behave, and increasingly they are opting for the convenience and pricing advantages offered by the online channel," comScore co-founder and chairman Gian Fulgoni said in a statement accompanying the news.

China's Alibaba, which includes Taobao and Alipay, was next with 156.7 museillion visitors, or 11.3 percent of total Internet users, followed by Apple with 134.2 million visitors, or 9.7 percent of total Internet users.

"Several global retail brands have already capitalized on this global consumer trend, and many other retailers are sure to pursue their share of the pie," Fulgoni said.