As Pages eligible for Facebook's in-stream ads grow, some brands say its brand safety tools lag behind YouTube, as Facebook focuses on increasing ad inventory (Max Willens/Digiday)

Max Willens / Digiday:
As Pages eligible for Facebook's in-stream ads grow, some brands say its brand safety tools lag behind YouTube, as Facebook focuses on increasing ad inventory  —  Ad buyers are getting nervous about how crowded Facebook's in-stream video program has grown lately.