SiliconBeat

According to Hitwise, a traffic measurement firm, visits to Google’s Gmail, long the smallest of the big online e-mail services, are accelerating. For the last two weeks, U.S. Internet visits to Gmail surpassed visits to YouTube, making Gmail the tenth most popular Website — in all categories — on the Internet in the United States.

While the numbers are sure to provoke new concern about Google’s growing dominance, they could make it easier for Microsoft and Yahoo to merge their Internet operations at some future time. Leaving aside the fact that Yahoo does not want to merge with Microsoft, one of the stumbling blocks to the deal proposed last year by Microsoft was the monopoly that a combined Microhoo would have in online mail.

Here are the latest rankings of the most popular Web sites from Hitwise for the week of March 7:

Google: 6% of all U.S. Internet visits
Yahoo Mail: 5 percent of all U.S. Internet visits
Yahoo: 3 percent of all U.S. Internet visits
MySpace: 3 percent of all U.S. Internet visits
Facebook: 2 percent of all U.S. Internet visits
eBay: 2 percent of all U.S. Internet visits
Windows Live Mail: 1 percent of all U.S. Internet visits
Yahoo Search: 1 percent of all U.S. Internet visits
MSN: 1 percent of all U.S. Internet visits
Gmail: 1 percent of all U.S. Internet visits
YouTube: 1 percent of all U.S. Internet visits