Internet advertising increased by 38% to $3.9 billion according to the Interactive Advertising Bureau and PricewaterhouseCoopers.

"Consumer habits are continuing to change and mature," said David Silverman, a partner with responsibility for assurance at PricewaterhouseCoopers. "Companies are effectively learning to devote more of their advertising budget to this fast-growing advertising platform in order to reach the right audience at the right time."

Annual spending on online advertising has been rising. In*2002, $6 billion was spent on Internet marketing and*$7.2 billion in 2003. In 2004, $9.6 billion was spent and*last year marketers spent $12.5 billion on the Web.