But see, the issue with thinking that is that it's only a security-blanket type of a cover that's doing almost nothing at all in the way of protecting from targeting advertisers and analytics companies, anyways. IP Tracking is not an efficient way for targeted advertising to happen. Google's better off doing this with cookies and other means (ie, places that you signed into with your Google account). IPs are subject to change at a varying rate (a day, two days, sometimes a month, two months)... and if this were the case, then we'd be seeing the same targeted ads for everyone that had our IP Addresses before us, as well as the person after us seeing our targeted advertisements.
IP tracking by Google comes more in handy for like abuse-prevention (ie, same person clicking on a link 30,000 times to drive up the costs or revenue) tracking.
If a user wants to be safe from ad tracking, the better answer is doing some general PC and internet browsing maintenance - explicit whitelisting of cookies from websites (this can be setup in your web browser to have it prompt you), or conversely blacklist the websites that you don't want to track you (ie, Google). You can also setup your browser to clear your cookies on each exit, or on a set schedule even, in some cases.