For any event where you have Graphical Stats enabled, one of the statistics pages is for "Estimated Social Reach."
So, how do we calculate this number?
Anytime a photo (or video or GIF) is shared to facebook, instagram, or twitter the helper app will gather that users friend/follower count (these numbers are shown in the Event Statistics .csv file in Event Manager.
Since not every friend or follower will see a given photo, we factor in an estimate that 30% of a users friends/followers will see any given posted media.
Additionally, many users will e-mail or text themselves a photo and then post it on social media. So for each user that e-mails or texts a photo we estimate 75 people will see it.
The overall calculation for estimated social reach ends up like this:
(# of Friends/Followers of every post) x 30% + (# of texts + # of e-mails) x 75 = Estimated Social Reach