Compete puts together a monthly ranking of the top 250 Web sites in the US, based on unique visitors, and breaks up the data by relevant categories and behavioral segments.

In its latest report, Compete found that the top performers for July fell into four main categories auto manufacturers that were part of the Cash for Clunkers deal, summer blockbuster movie sites, backtoschool shopping sites and social media news aggregates like Digg or Tweetmeme. Marketers need a mechanism for spotting consumer trends as soon as they begin to emerge, especially as the U.S. economy starts down the uncertain road to recovery, says Cynthia Stephens, director of Marketing for Compete.