ValueClick will pay $3.3m (拢2m) cash and take on debt at the company, which operates a search engine where advertisers bid for priority placement on search result pages.
ValueClick said that Search123, based in California, would be a great fit with the company.
James Zarley, chairman and chief executive officer of ValueClick, said: "I believe the addition of Search123 rounds out our array of media offerings and enhances our position as a single-source provider of media service and technologies for online marketers."
There are no plans at present to launch Search123 in Europe.
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