How effective is paid advertising anyway?

Scott Cunningham, on the selection bias in paid clicks:

"""
[..] there was a nearly one-to-one increase in natural clicks [..] as though users were already going [..]
"""

https://causalinf.substack.com/p/how-can-we-know-if-paid-search-advertising

Reminds me of 2020, when in the Netherlands the NPO (national broadcasting service, akin to BBC), removed third-party tracking and actually increased their revenue in doing so: https://techcrunch.com/2020/07/24/data-from-dutch-public-broadcaster-shows-the-value-of-ditching-creepy-ads/

#google #facebook #ebay #AdTech