Facebook Insights has “unique metrics" available. These are metrics that have a unique value, such as the unique people who engaged with your page. You can find a list of all unique metrics at the end of this article.
Facebook unfortunately only provides totals for these metrics for a few specific time spans. The values shown in their interface and returned by their API are based on sampling, and are therefore estimations. As this is based on data at Facebook internally, this means we also cannot calculate a 100% accurate total for these metrics ourselves!
There are a few date ranges that will result in the most correct totals Facebook has available. If you select date ranges that span exactly 1, 7 or 28 days, we can fetch their total from Facebook. Facebook doesn’t provide values to calculate an accurate enough estimation unfortunately, so for date ranges with different lengths, we sum the values returned.
Because of possible inaccuracy, we will soon show a ~-sign to indicate the value we show is an estimation, as we cannot guarantee the accuracy of the values shown for unique metrics.
Want to get a total as accurate as we can provide? We recommend using date ranges of 1, 7 or 28 days exactly for your Facebook Insights reports.
Unique metrics:
Unique action button clicks
Phone number clicks
Get Directions clicks
Website Clicks
Engaged user
Unique consumptions
Total Unique Check-Ins
Unique Check-Ins (Mobile)
Unique negative feedback
Unique positive feedback
Reach
Paid reach
Organic reach
Viral reach
New stories
Page likes
Unique new page likes
Unique page unlikes
Unique video views
Unique 30-second views
Unique page views (Logged in)
Fan reach
Post reach
Unique fan impressions
Paid fan reach
Unique new stories (Talking about this)
Unique organic views to 95%
Unique paid views to 95%
Unique organic video views
Unique paid video views
Unique 10-second video views
Page posts reach
Paid page posts reach
Organic page posts reach
Viral page posts reach