In 2005, US Internet advertising spending will surpass $10BN for the first time, and perhaps reach as high as $12.9BN, according to projections in  a new report, Ad Spending Trends: The Internet and Other Media. That number more than doubles 2002's $6.0BN figure.

Four years from now, says the report by eMarketer, companies will spend nearly $10BN more on Internet ads, reaching $22.3BN in 2009.

Four basic trends, the report finds, are supporting the continued growth of Internet ad spending:

1. Larger ad budgets overall
2. Shifts in ad budgets from other media to the Internet
3. More companies including the Internet as part of their campaigns
4. Increased prices for both branding ads (display and rich media) and direct response vehicles (such as paid search)

"The spending growth is impressive, but shouldn't come as too great a surprise," says eMarketer senior analyst David Hallerman, author of the report. "These dazzling increases are possible in part because growth came from such a small base. And in the last few years the Internet has truly become a mainstream medium."

According to quarter-by-quarter historical data from the Interactive Advertising Bureau and PricewaterhouseCoopers (IAB/PwC), US Internet ad spending has increased in eight of the last nine quarters. And eMarketer projects continued gains through 2005, with fourth-quarter spending hitting a record $3.8 billion.

"To call this advertising market 'hot' implies it's a fashion that might turn slack at any moment," Hallerman adds. "These yearly and quarterly ad spending gains point to a sea change in media usage among marketers, reflecting how the Internet has become an essential element of daily life for more and more individuals."

Other questions addressed in the Ad Spending Trends report include:

• Where is the money coming from to support increased Internet advertising?
• When will the Internet's share of total media spending surpass the 5% mark?
• How long can Internet Advertising keep increasing by 20%-plus each year?
• What trends will most influence total media ad spending?
• Which companies are investing the most ad dollars in which media?