[thanosnose]

> Does anyone know how effective incognito mode is at preventing data and privacy abuses like this?

Incognito mode really doesn't do much. It only prevents storing browsing data locally on your computer. Your ISP, your search engine and the websites you visit can store your info on their servers.

> but I imagine there may some clever ways of tracking even across incognito sessions (or between incognito and regular).

Browser fingerprints, IP address, etc are used to track you. Your ISP doesn't even need to be clever since you are dependent on them for your internet connection. There are ways to "hide" yourself from websites, search engines, etc but it's nary impossible to completely "hide" from your ISP.