As the topic suggests, I was wondering whether there is a factual relationship between accelerating E-Commerce penetration, caused by the COVID shift in consumer buying behavior and performance marketing cost (i.e. FB / Instagram / Google). It seems obvious enough that the two should be interlinked but I was wondering whether there are any statistics / research around the topic and particularly its magnitude. E.g. for a 1% increase in E-Commerce penetration, there is an expected X% increase in performance marketing cost.