COMSCORE Inc. (NASDAQ:SCOR) has released its June rankings of the power and reach of Web properties. The report measures the reach of the world’s most prominent websites, and tracks the power and reach of various online advertising services.

Not surprisingly, Google Inc (NASDAQ:GOOG) retained its number one spot, with its various sites getting 189 million visitors in the month. The company’s top rival in traffic was Yahoo! Inc. (NASDAQ:YHOO), that company’s sites received 167 million visitors in June.

Microsoft Corporation (NASDAQ:MSFT) was in third place with 166 million visitors, while Facebook Inc (NASDAQ:FB) had 160 million visitors. The top five was rounded out by AOL, with just 113 million visitors.

Other big web players on the list included Apple Inc. (NASDAQ:AAPL), at ninth place with eighty million visitors, showing a rise from tenth in May, Wikimedia at eight sites with eighty three million visitors, and Inc. (NASDAQ:AMZN) at sixth with just over one hundred million visitors.

The report revealed the expected rise in visits to leisure oriented sites as Summer officially began. Zynga Inc (NASDAQ:ZNGA) saw an increase of 103% in visits to its sites. The total number of visitors was 14 million in June as Americans chose to spend their leisure time playing the company’s popular online social games.

Other big winners from the seasonal trade included travel sites such as Americans planned for trips throughout the Summer break. Websites specializing in ground and cruise travel saw the largest sectoral rise in visitors, with a 9 percent bump. Train service provider, Amtrak, was the biggest recipient of extra visitors in the category.

Hotel and Resort centered websites were the second biggest risers in the month with a bump of 8 percent. Hilton Hotels, a subsidiary of the Blackstone Group L.P. (NYSE:BX), claimed the number one spot in that category. Hilton sites saw 5.5 million visitors in the month of June.

There was a related Summer increase in visitors to sites across the leisure spectrum, from sports and outdoors, to toy companies. On that front Toys R US, owned jointly by Bain Capital LLC, Kohlberg Kravis Roberts, and Vornado Realty Trust (NYSE:VNO), came in at number one.

The most interesting, and probably most important, part of comScore’s report is the advertising permeation of the internet’s biggest marketing companies. This metric is the one that means the most to many of the world’s biggest tech companies.

Google was of course a distant first in the “Syndicated Ad Focused Entities” section of the report, with a heady 82.4% reach. The firm’s closest rival was ShareThis, with 78.9% reach, and Yahoo rounded off the top three with its respectable 75.6% reach.

Facebook remains a distant fourth in the category despite pinning its hopes on penetrating the global ad market in order to boost revenues. Facebok’s reach was clocked at 72.3%. A distant fifth in the category was Google’s Youtube ad service. That business commanded a distant 58.1% reach.

The numbers reported by comScore do little to inform of the real value of the advertising or of the visitors on any single web site. Those numbers need to be computed in more specific contexts. The figures do, however, provide a reasonable view into the comparative reach of websites and their ability to retain their visitors.