Is Click-through the right metric for marketing success?

According to the case MedNet.com confronts "Click-Through" Competition, we can see that Windham Pharmaceuticals care much for the click-through rate and require MedNet to consider their pricing strategy or they will do business with MedNet's competitors.

But “A click means nothing, earns no revenue and creates no brand equity. Your online advertising has some goal—and it’s certainly not to generate clicks,” said John Lowell, Starcom USA SVP and director, research and analytics, in a statement.

In this article, we can see that even the heavy clickers on online advertising ads only account for 4% of Internet users in the US but they are responsible for 67% of click-throughs on March, 2009. And only 16% in Internet users in the US click on online advertising ads, does it means the numbers reflect the true prospects for the products and attracted by the advertising?