Based on the sputtering economy, eMarketer dropped its estimate for 2008 online ad spending in the U.S. by a nice, round billion bucks. The earlier estimate, from March 2008, called for $25.9 billion, while today's number is $24.9 billion.

"Even as the potent mix of a misfiring economy and consumers' changing media habits shave advertising dollars from traditional venues, such as newspapers and television, Internet ad spending will continue to grow rapidly," said David Hallerman, senior analyst at eMarketer.

eMarketer strove to put a good face on the news, calling the figure "slightly lower" and noting that it still represented a 17% year-over-year increase. but let's face it: A billion dollars is a billion dollars.