July 2011 marks the first month of Nielsen’s new “Total Internet Audience” metric, which incorporates hybrid audience measurement data to provide a holistic view of online audience activity. Google was the most visited website in the U.S. in July with 172 million unique US visitors. During July 2011, 7 of the Top 10 web brands retained the same rank, with Wikipedia and Apple switching places compared to previous months. Amazon had 70.4 million unique US visitors during the month, making their site the 10th ranked during the month.

Hybrid data extends beyond Home and Work PCs, and as a result of these measurement enhancements and the additional sources measured, metrics including Unique Audience, which Nielsen uses to rank the top web brands, witnessed changes in data for July. Therefore July data can not be trended, but moving forward Total Internet Audience data can be trended with previous months’ Total Internet Audience data.

Hybrid measurement combines Nielsen’s online panel, a people-based representative sample employed to measure consumer’s Internet behavior using Home and Work computers, with tag-based data from websites to account for Internet use from any source. Thanks to this hybrid approach, Nielsen’s Total Internet Audience metric includes web browsing activity from all devices, including mobile devices, tablets, secondary PCs and access points outside of home and work locations.

Overall 213 million Americans were active on the Internet in July 2011 from all sources included in hybrid measurement. Internet access through home and work PCs continued to grow to 249 million individuals in the U.S. during July 2011.