Online is sometimes a victim of it's own accountability. It can be hard to navigate in a blizzard of metrics, and putting measures against social media is even tougher. In the old world, our measures were constant, controlled, fixed, familiar, steady. Social media is fluid, moving, changeable, unexpected. Campaigns used to be nicely packaged entities. They had a beginning, middle and an end. Good social media campaigns increase their value over time and are far from short-term. But in the current environment of test-and-learn, measuring is the only way we know what works.
So what's the answer? One things for sure, click rate in isolation isn't it. Trying to enforce old media methods, or even basic new media metrics will not tell you anything that's worth knowing. Measuring the effectiveness of social media campaigns is going to involve a whole new cocktail combining hard and fast metrics like visitors, click-throughs, time spent, interactions, pass-alongs, embeds, games played, videos watched, groups joined, with judicious use of bespoke metrics, qual measures, and the whole host of new (and free) metrics which are out there. The smart will understand that the more custom the blend, the greater the knowledge.