According to a 2005 report by PricewaterhouseCoopers, 385 billion dollars are spent on advertising annually. This report estimated that by 2010, worldwide advertising spending will exceed385 billion dollars are spent on advertising annually. This report estimated that by 2010, worldwide advertising spending will exceed 500 billion. As you can imagine, such a gigantic flow of money requires a similarly gigantic infrastructure. Of course, the most common advertising formats—print, radio, and television—have a relatively long history, with a very entrenched methodology for analyzing how money is spent. On the other hand, web advertising is a relatively new phenomenon, and many organizations do not have a coherent system for tracking Internet advertising.