In most cases the same information you can glean from someone’s email inbox, you can likely glean the same accuracy by looking at their google search history.
I would guess Google doesn’t read emails because the data is more difficult to parse (there’s a lot of it) and, when compared to intent based interests that can be gleaned from your google searches, the value of the content in your inbox is lower than most people think.
I would guess Google doesn’t read emails because the data is more difficult to parse (there’s a lot of it) and, when compared to intent based interests that can be gleaned from your google searches, the value of the content in your inbox is lower than most people think.