WebProNews

comScore Media Metrix released its top 50 web properties for the month of June. It's no surprise that Google sites remain on top with Yahoo and Microsoft in the second and third positions respectively.

Facebook has moved up 2 positions to number 6 though, giving the social network its highest ranking to date. Twitter actually just made its first appearance on the list, coming in at number 46 with 20.1 million visitors.

"It's hard to believe that Twitter.com had fewer than a million visitors in June 2008, and now attracts more than 20 million visitors a month and ranks among the top 50 U.S. properties," says Jack Flanagan, executive vice president of comScore Media Metrix.

"Twitter has clearly been able to generate wide interest and cultivate a substantial following in a very short period of time," he adds. "If this momentum persists, then we will continue to see Twitter climb higher and higher in this ranking in the coming months."

Also worth mentioning is that travel sites jumped in June, although this is not incredibly surprising. "Travel sites typically see an increase in activity around this time of year as Americans look to get away," says Flanagan. "Summer vacation also means more leisure time for those out of school, leading to a seasonal increase in leisure categories including online gaming and entertainment."

Notice that career categories made gains as well. This is also unsurprising, considering the state of the economy and unemployment.