CelebrityNetWorth.com was a popular, data-driven website whose 12 staffers led serious efforts to research public figures and give a credible estimate of their fortunes. Google liked the look of this, so it made site founder Brian Warner a proposition: let Google include the Big Number as a featured "snippet" atop relevant search results, in return for the snippet linking to the website.
Warner, though, knew that the link offer was worthless and said no. Mysteriously, Google started "answering" questions about celebrities' net worth anyway, only occasionally disclosing the source; he seeded his database with a few fake celebrities to prove Google was using CelebrityNetWorth.com's data. The result was just as he predicted when he said no: his site's lost most of its traffic, even as Google depends on it to provide accurate answers.
Google's push into direct answers has wide-reaching consequences for more than just small business owners who depend on search traffic. The email Google sent Warner in 2014 gives some insight into how Google selects reputable sources. Google wouldn't answer questions about this, but based on the emails, the vetting was pretty thin; Google seemed more interested in whether the data was machine-readable than whether it was accurate. And the bar for featured snippets — the answers culled algorithmically from the web — is even lower, since it appears that any site good enough to rank in search results is good enough to serve as the source for Google's canonical answers. That's how you get erroneous answers that claim Barack Obama is organizing a coup, or that the Earth is flat, or that women are evil…
Seems like there's a linear relationship between Google rehosting your content and website traffic going down.