The four basic search options are paid search, contextual advertising, paid inclusion - all three are types of advertising - and search engine optimization (SEO). All four options will experience increased spending through 2013. By then eMarketer estimates total US search marketing outlays will surpass $23 billion.

?Customers are going to search engines because they are looking for better deals,? says Mr. Hallerman. ?And marketers are going to search engines because that?s where the customers are.?

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