Many website owners will often display a fake feed subscribers count on their website to increase the potential of their website getting more feed subscribers.
I can’t think of any good reason why anyone would want to know about a number of feed subscribers for any website. May be if a subscriber count is too high for a low traffic website, then you might want to find out if its a fake count or not.
There are many feed subscriber counters available for use on website, but not all website owners keep those for live display of the stats.
So the easiest way of counting the real number of RSS feeds subscriber is by simply adding ~fc/ right before the feeds ID.
For example:
Here is the feeds link for this website from feedburner: https://feeds.feedburner.com/Ing-base
As of today there are 3 subscribers which is fine considering this website along with its content is just 2 months old.
And if you want to check the number of subscribers then here is the new link that contains ~fc/
https://feeds.feedburner.com/~fc/Ing-base