A. Semi , Quattro Wireless , C3 Technologies , and, according to rumors, Siri .

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Apple also purchased mobile advertising Quattro Wireless, moving into a business Google has pursued.

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In January the firm snapped up Quattro Wireless, which specialises in advertising on mobile handsets.

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Miller was co-founder and CEO of Quattro Wireless, a mobile advertising company acquired by Apple in 2009.

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Quattro Wireless did not immediately respond to a request for comment.

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