Online adspend continued to rise in the first quarter, increasing for the ninth straight quarter and reaching $2.8 billion, according to Interactive Advertising Bureau and PricewaterhouseCoopers revenue estimates based on sales reports from online publishers and other internet media providers, AdWeek reports. The $2.8 billion estimate is the highest reported for a quarter - and a 26 percent increase from the first quarter of 2004, as well as a 4.3 percent from the previous quarter (4Q04), traditionally the highest in adspend because of holiday promotions.

The IAB and PwC attributed the increase to a larger online audience and the growth of broadband, which allows marketers to deliver brand advertising to a mass market once targeted only via television, CNET writes. As the TV audience fragments because of cable and satellite channels, marketers can more cheaply target the growing number of customers who are online, including via search engine marketing. The IAB reported web ad sales of $9.6 billion for 2004, up 33 percent from 2003.

Online ad spending forecasts for 2005 have varied, but all researchers have estimated significant increases. Last week, Goldman Sachs raised its forecast, predicting 28 percent growth for the year and a $12.3 billion market - 4.4 percent of total U.S. adspend. Forrester Research has forecast sales growth of 23 percent, reaching $14.7 billion. eMarketer pegged growth at 34 percent, or $12.9 billion for the year.