Online advertising will grow 23 percent in 2008Online advertising spending will reach $25.9 billion in 2008, up from $21.1 billion in 2007. Search marketing accounts for 40 percent of that amount. Video ads, about 10.2 percent of the market this year, will account for 18.5 percent by 2012. Display advertising's share, at 21.1 percent, will remain flat through next year. [paidContent]