I had an experience with a national meteo application including facebook trackers. I complained and they replied that they were totally unaware of that fact. The tracking was added by default by the contractor as part of his standard template. (note: they removed the tracking after my complain).
But it is also about people in charge, who are completely addicts to statistics about the number of visitors and all information. People like to track others. They actually want that.
The sad part is that nobody in IT really complain nor tell them that it is creepy. We install blockers on our own computers and get over it, writing code that track those without blockers without batting an eye.
Which may be because if you do, you will typically be called the "technical person" who "doesn't understand anything about 'normal' users" and you should be more focused on your actual technical tasks.
Sorry for being cynical. I couldn't resist.
Why? What will you improve by knowing that, and why couldn't you improve that without knowing it?
There’s 90% chance that no, it’s not your business. There’s also a lot of chances that your website is about a product. In which case, it doesn’t make sense to know how many people come and read. People only need the information to know "will I buy that or not?" or, even more frequently "I’ve bought that but I don’t understand something".
Tracking is counterproductive in most scenarios. (but very few understand that)