Looking at the Blue Flame popularity number is a great way to quickly judge the popularity of pins in your Communities. You can find it by looking at the top right corner of a Pin in a Community.
The Blue Flame count updates usually every 24 hours, and counts the number of times the exact source URL for that Pin appears on social networks. This generally matches the number of shares you'd see in a blog social share counter (like Social Warfare).
Due to the large number of Pins we track - we update the Blue Flame number once every 24 hours or so - so there can be a short delay before you'll see the latest updates come through.
There can also be a difference in what you see Blue Flame count vs other methods - as we only count URLs which match that Pin exactly. Meaning if anyone else shares the same source, but includes something like their own Google Analytics tracking code as an example (eg: a UTM code appended at the end of the link), this will be seen as a different URL and not be included in our tracking. Whereas this may be included in other methods you're using to determine the number of shares.
Want to know more about how the Blue Flame number is calculated? Check out our Knowledge Base article: What does the Blue Flame represent on my Community's Pins?