Only up to the limits of Google being able to track you anyway. There's IP address, user agent, and any other HTTP header information your browser leaks.

A VPN + Incognito should be enough. Not to truly anonymize you, but probably enough to disable the personalization layers. It doesn't make economic sense to waste engineering hours and computing time trying to show ads to the 0.0001% of paranoid users, which are likely blocking them anyway, even if the data is there.

Of course, there's no such thing as the vanilla user. You'll still be targeted on generic features (location, browser, OS, etc). A vanilla Linux user in SF is different than a vanilla Windows XP user in London.

The EFF has a service called Panopticlick[1] that gives you a sense of how unique your browser looks to the sites you visit. My result: "Within our dataset of several million visitors, only one in 886,262 browsers have the same fingerprint as yours."

[1] https://panopticlick.eff.org

Well, if the rate holds for Google, it means there's 1320 users that look just like you.

While it can be an issue, browser fingerprinting isn't as powerful as the EFF claims. Any change to your user agent (browser updates), plugin list, time zone, or screen size makes Panopticlick think you are a different user.

Correlated with a second or third tracking method such as cookies sent to analytics, ad and fb sites, would it be super sticky?

I don't get why people recommend VPNs so much. I never bothered to look for a free one because I didn't think it'd have a decent speed and all ports opened, but doesn't Tor basically do the job?

Free ones probably suck, but even a very cheap (<$50/year) VPN will be much faster than TOR.

It still feels double to pay for an internet connection and then a second time for a VPN, but yeah it might come in handy. Still think I'd go for a VPS instead and, if I need a VPN, just tunnel it through, but that's just me.

Well, I said VPN has a catch-all for using a remote gateway. I actually use a VPS as well (with sshuttle).