“In a custom report created for ClickZ News, Hitwise measured traffic market share of the candidate sites. The measurement firm found traffic to Democratic candidate sites was top heavy, favoring Clinton’s, Obama’s and Edwards’s sites. HillaryClinton.com garnered nearly a third of visits among Democratic candidate sites in May. BarackObama.com attracted almost 28 percent, and JohnEdwards.com drew 23 percent of visitors to Dem campaign sites last month.”