You can't be serious. Who in this day and age reads an article and thinks "Hmm, that was useful, I'll send the author a note of thanks"?
This might have been the case in 1995 when there were only a few websites around, and Internet use was considered leisure time and not part and parcel of everyday life.
I do. Maybe you should, too?
https://www.reddit.com/r/chomsky/comments/6a23eg/how_long_do...
I also pull comments from LessWrong and Facebook, though the FB comment integration is pretty temperamental.
Without that, you'll loose a really strong signal for self improvement, and your blog might become write-only...
Certainly if you're looking to build an audience, then the popularity of your posts is an important metric that will help you craft additional popular posts.
But it seems to me that the the only _quality_ indicator isn't a metric at all - it's actual feedback from people who have read what you've written.
You can delve into metrics like the time spent on a page but in the long run popularity is the king since it also reflects dwell time.
But metrics and statistics are the very foundation of science, and the graal of software engineering. I can't resist the temptation of knowing which browsers and the countries of the users of my website, or how many hacker news visitors come to it every other season, so many possibilities... sigh
No need to snitch on your visitors to big G.