- Adweek Staff

As recession-weary advertisers continue to keep close watch on the purse strings, search marketing becomes the best customer acquisition tool in the online space, according to eMarketer.
 
The four basic search options are: paid search, contextual advertising, paid inclusion--which includes all types of advertising--and search-engine optimization (SEO).
 
While paid search gets most of the attention and money, marketers will look increasingly toward SEO as they look to acquire new customers.
 
U.S. spending on search-engine marketing will nearly double from $12.2 billion in 2008 to $23.4 billion by 2013. What's more, all four types of search marketing will gain more marketing dollars each year.
 
As advertisers better understand the impact of Web site optimization on the success of their overall campaigns, spending for SEO will grow more each year compared to the three other types of search marketing--and more than the total online ad market.