Based on data from one or more of your connected Facebook Business Tools, the number of spend credits events ascribed to your ads. This does refer to the overall amount of credits spent. This metric tracks spend credits events that are ascribed to your advertisements and tracked by one of your Facebook Business Tools (such as a Facebook pixel, Conversions API, app SDK, or offline event set). Depending on the attribution setting chosen, events may be counted differently. In some cases, statistical modeling can be used to account for occurrences that cannot be counted directly due to incomplete or missing data. This metric may not be calculated in some cases, such as the results presented for iOS 14 campaigns.