I can measure how many people saw this post, where they are from, their operating system and how long they spent on the page, how many of them returned, etc.
I could also measure your enjoyment while reading this page, perhaps with a star system like this ⭐⭐⭐⭐⭐, where more stars mean more enjoyment. This seems straightforward enough.
The right question is:
Is this important ?
Probably not. Certainly not important enough for me to re-design the whole site to get more 'of them'. With measurement comes the idea of performance, and performance drives a quest for improvement.
Seeking improvement is the essence of life; unfortunately improvement is extremely difficult to measure. In yesterday's post Easy vs. simple, I said that easy is lazy, and this is the problem at hand here.
We measure what is easy to measure, because, well, it's easy.
But easy does not mean important.