Historically, the most popular metric of Web marketing has been traffic. How many visitors come to your Web site each month? How many unique, how many repeat?
This is how the Web grew up, with "hits" as a common denominator across all properties. The more you have, the better you are. Simple math.
Web advertising has been primarily concerned with feeding this engine of growth. The overarching mission of click marketing has been to drive traffic to an organization's Web site. Keep the number of clicks high and the cost-per-click low.
The implicit assumption has been that if you get enough traffic to your site—the right kind of traffic, even more so—then Web advertising has succeeded, and it is now up to your site to take over from there. Because this hand-off is viewed as independent, the teams running the advertising may very well be different from those managing the site.
But that assumption is rapidly evolving.
Demand for traffic on your Web site isn't likely to subside, but that's not necessarily the objective for every online ad campaign anymore.
Increasingly, Web marketing campaigns are measured by leads generated and sales transacted. These metrics have been tracked for a while, but what's remarkable now is the proliferation of end-to-end campaigns that don't drive traffic to the organization's main Web site at all.
These end-to-end campaigns exist as standalone microsites, encapsulating everything relevant to a particular pitch—and nothing more—in a focused presentation for a specific target audience. The yardstick of success is the percentage of conversions.