I'm sure the banks would love to do this, but I'm not sure the trackers the GP mentioned actually share any of this data back to the site. Facebook stalks everyone for their own benefit but are usually pretty good about keeping that data to themselves.
Maybe you have an 18% greater risk of default, if you visit sites about poker?
Only the big boys have tracking on all sites, so only they can report back everyplace you visit.
Of course, it doesn't matter if you were just doing research for a paper, you now pay higher interest rares.
Banks also are one of the few places where your ID is 100% known upon login. So they are a perfect place to take loads of tracking info, and:
- link it back to your real ID
- your credit report
- your physical address
- your birth date
- things like home ownership
- all bills you pay
- using debit or cc, where you shop
They have an immense business model, where they link online tracking, to meatspace habits.
As well, since your bank often gives you points credit cards, and stores cooperate for fee discounts, often individual purchases are known.