Around Labor Day my CPM on all of my Facebook campaigns seemed to increase pretty dramatically. I did some split testing and switched to Lookalike audiences that lowered my CPA and increased my result rates but the CPM continues to stay around $25-35 (up from $8-16).
Any ideas why this could be? My initial thought was just increased advertising competition around fall and going back to school etc, but now I'm not sure.
Should I just try to ride it out or is there something I can do to lower it?