Why click-through rate isn't the metric you think it is

Click-through rate is the first number everyone reaches for, and the last one that should decide anything on its own. A link with a 12% CTR and a link with a 3% CTR can perform identically once you look at where the clicks came from and whether they went anywhere useful afterward.

CTR without context is just vanity

A high CTR on a link blasted to a huge, untargeted audience is often worse than a low CTR on a small, qualified one. The rate rewards volume, not intent. When you judge a link by CTR alone, you optimize for the wrong shape of traffic.

The two numbers hiding behind it — source quality and downstream action — are the ones that predict outcomes. urlr's referrer and country breakdowns exist precisely so you can see past the headline rate.