This is an interesting discussion -- let me add that today, search ads are the highest performing ads on the Internet, perhaps the world. Yet, only 4% of consumer's time is spent in search engines. Search retargeting enables advertisers (including small to large size businesses and enterprises) to do is to take the power of search and apply it the remaining 96% of ad inventory (includes news and content related sites, social networks, etc.) where users spend there time. This allows advertisers to capture the search of a user and follow up with that particular consumer who has already shown interest in a product or service. In a recent automotive campaign, search retargeting outperformed a non-targeted display campaign by 150%. If you need more information on search retargeting, let me know.