Before email and the Internet, direct marketing was such a different marketing channel. Old school tactics like call centers and direct mail flourished on the premise that a very small response rate (2%ish) could lead to a profitable program. That formula worked for a lot of companies, for a very long time; particularly for organizations that invested the time to refine their campaigns. The discomforting part was that with direct mail you still had to pay to mail to the other 98% of your list and with telemarketing, the nonproductive calls still had to be made.
In case you are unacquainted, Remarketing involves placing ads on other websites through networks like Google AdSense. The ads appear when people who have visited a site, but haven’t “converted”, visit other sites that participate in the content network, such as the New York Times or Microsoft’s partnership with sites like The Wall Street Journal. Behind the scenes, a cookie is dropped on a visitor’s site, which provides the marketer the ability to “remarket” to them on other websites.
The volume of traffic from Remarketing may not be large compared to other sources, but the quality tends to be impressive, as these individuals have been to your website (or landing page) already. The response rates will likely even better if the message in the “remarketed ad” is aligned with the website section / product that was viewed originally.
From an historical direct marketing perspective, and given the targeting efficiencies, the logic of Remarketing is fundamental.