They block one vector of tracking. They don't block CDN-based tracking: http://blogs.wsj.com/digits/2010/11/30/a-new-type-of-trackin... (note the juxtaposition of "new" and "2010")
Google's entire business is based on building large database of tracking (and other) information; obviously their DNS is just another data source.
Just skip the recursive resolvers and run a local caching DNS server that starts from the root zones.
And the IP may be a public network.
Only if you allow third-party cookies. I'm honestly amazed that browsers haven't moved to turn third-party cookies off by default.
https://www.akamai.com/us/en/about/news/press/2013-press/med...
"As a result of the pixel-free technology partnership, MediaMath's clients will gain access to more data for audience segmentation, retargeting, and optimization, with quick and easy activation."
https://addons.mozilla.org/en-US/android/addon/decentraleyes...