Facebook reveals more metric bugs: Reach, full video views and Instant Article engagement takes a knock

Facebook has admitted further publisher engagement discrepancies which raises additional questions about the first-party data the company is transmitting.
In September, there was a backlash when the company revealed a substantial failure to accurately measure video engagement times (overstating them from between 60 to 80% for two years).
Now, the Wall Street Journal reports that an internal Facebook audit has found that the company inaccurately measured said brands’ as a result of 'bu