Spending on online advertising in the fourth quarter soared to a record $3.6 billion, 35 percent more than in 4Q04, according to an Interactive Advertising Bureau and PricewaterhouseCoopers report issued Wednesday, writes MediaPost. Internet ad spend for the year totaled an estimated $12.5 billion - a 30 percent year-over-year increase.

That was slightly lower than 2004's 32 percent growth. The IAB predicts that ad spend growth will slow, likely increasing in the 20+ percent range.

In the last five years, the 2Q04 had the highest growth in online ad spending, increasing 43 percent compared with 2Q03.