Legacy Facebook Conversion Metrics not accurate
We have noticed some older conversion metrics are no longer supported by the API, this means that the conversion data shown in Adpulse might not match what is in the Facebook UI for these cases. Unfortunately, as this is a restriction of the API, there's not much we can do to fix this data.
Below are the instances that we have discovered so far:
Estimated Ad Recall Lift (People)
The API only returns daily data, but summing this over a date range does not equal the value the Facebook UI displays when using a date range. Facebook seems to apply another algorithm when using date ranges and that is not included in the API.
What works: Looking at data for a single day, Adpulse will have the correct value
What doesn't work: looking at data for a range of dates, the Adpulse data will not match the Facebook UI
Solution: This is a legacy conversion objective, no longer supported by Facebook, so we'd recommend replicating the campaign using the current objectives.