Disappointed that Firefox is giving Cloudflare user DNS resolution data by default via DoH. I trust my ISP but if I didn't, I'd use a trusted VPN to protect *all* my traffic. DoH is just a DNS-only VPN. What's worse, if you do use a VPN for #privacy FF will still leak your DNS data to Cloudflare by default. https://blog.mozilla.org/futurereleases/2019/09/06/whats-next-in-making-dns-over-https-the-default/
Ask yourself why all these companies are fighting each other to be your default DNS provider. Why do their "privacy" solutions always give them your data instead? It's valuable data and it's easy to control it yourself. #privacy https://www.linuxjournal.com/content/own-your-dns-data
@jeremiahlee Cloudflare says they don't sell it for ads, but to answer your question in general, the value is the association of a series of websites with an individual, even if you don't know *who* the individual is.
Advertisers find a lot of value in "someone who likes X also likes Y but doesn't like Z" so that when they do have a target in mind that likes X, they know to market Y to them but not Z. This is why social graphs are valuable--friends/colleagues often share preferences.