Here’s How Google Will Place a Million Dollars’ Worth of Ads checkmyads.org

Nandini Jammi and Claire Atkin of Check My Ads:

For about 2 weeks in Q3 of 2021, Sebastian (not their real name) accidentally ran a Google ad campaign for his client without any of the usual guardrails. He blew through a million dollars of the client’s budget before realizing that he had forgotten to turn on the brand safety filters, domain blocks and keyword blocklists he normally uses. It was a mistake.

He got it under control ASAP, but in those 15 days, Sebastian unintentionally obtained the results to an interesting experiment: where does Google place $1M worth of ads when you leave it up to them? What happens when you let Google place ads for you? Thanks to Sebastian, who sent us the sitelist of his botched campaign, we now have an answer.

The second most popular placement is a bucket of “unknown” websites. Apparently, Google knows which websites these are and all of them are allowed to show ads from Google, but website owners are able to prevent advertisers from knowing which sites received their spending.

The most popular site for this campaign? You will never guess.