Online advertising among the top 10 auto manufacturers accounted for just 2.5 percent of their total ad spend from January to November 2005, but in part because of tight online inventory and higher prices, eMarketer estimates that they will spend $2.7 billion in total online advertising in 2007, nearly twice the $1.4 billion they spent in 2005 - or 15 percent of all U.S. internet advertising spending in 2007. "Automotive advertisers are gearing up for an online advertising surge, but it's going to come at the expense of other media," said Lisa E. Phillips, eMarketer Senior Analyst and author of the "Automotive Online: Gearing Up for Greater Spending" report.

eMarketer forecasts that in 2006 automotive internet advertising will reach $1.95 billion, up some 35 percent from the previous year - and accounting for 12.5 percent of all U.S. online advertising in 2006.

"The automotive industry is the largest advertiser in the world. In the U.S. alone, the industry spent more than $17 billion in the first 11 months of 2005," says Phillips. "But, despite the fact that almost 70 percent of consumers use the web at some point in their automotive purchases, the industry has been slow to commit to online advertising and promotion."