Google is the advertiser. Just replace the word 'Google' with 'Doubleclick'. It starts to make sense.
When you use mail.doubleclick.com for your email, and www.doubleclick.com to search the web, all from your DoubleClick based phone, its pretty easy to understand the situation.
Nobody here is under any misconceptions that Google doesn't get most of their money from advertising - where we diverge is what their overall mission is and how good or bad those ad tactics are, and if they represent a good tradeoff for the services they provide.
Personally, I've got no issues letting them build a better profile in return for some of the best web services out there. I owe my career to the excellence of their search product.
What often gets ignored in that value judgement is that the profile can lead to more relevant search results. (Subjectively, Google's results get better when I'm signed in.)
At least for me, using DDG is like stepping back into the 90's as far as search result quality goes.
When you use mail.doubleclick.com for your email, and www.doubleclick.com to search the web, all from your DoubleClick based phone, its pretty easy to understand the situation.