Internet ad revenue up 34% in 2006

U.S. online advertising revenue climbed 34% to $16.8 billion during 2006, according to an estimate released Wednesday by an industry trade group.

Online ad spending in the fourth quarter was nearly $4.8 billion, up 32% from a year earlier, the Interactive Advertising Bureau reported.

Advertisers have been steadily shifting more of their budgets online to follow the increasing numbers of people who are spending more time on the Internet instead of watching TV or reading printed newspapers and magazines. Online ad revenue in the United States has more than doubled from $7.3 billion in 2003.