I'm sure you already know the answer, but the more data they can collect on you the better. If they are technically capable of building out a full profile on yo

I'm sure you already know the answer, but the more data they can collect on you the better. If they are technically capable of building out a full profile on you, they can use it to recommend products, make credit decisions, etc. Favicons is only the tip of the iceberg - download ghostery and see what 3rd party scripts are running. Like a ton, including some from oracle that connect you to all their data in their device graph. So even if you used a brand new phone and logged into your account, all your previous history would be tied to your new phone and vice versa.