Comment by tomrod

This is an open secret among techonomists and others in the arcane space of digital campaign measurement.[0][1- preprint] Digital advertising has a lot of smoke and mirrors. There is _some_ incrementality, but it seems oversold.

[0] https://academic.oup.com/qje/article-abstract/130/4/1941/191...

[1] https://papers.ssrn.com/sol3/Delivery.cfm/SSRN_ID2498290_cod...