Has anyone ever read the report on what data on you that the likes of Facebook correlates in a few milliseconds once you sign on? It is staggering and in some places it includes all your recent Credit Card purchases. All so it can target ads at you. Google does the same.
Other companies are doing this but to lesser extents.
Using cash does not leave a trail especially for small transactions where you pay in coins. Even tracking small denomination notes is almost impossible especially if you get them in change from a previous transaction.
I don't want 'the man' (or any commercial company) to know everthing about me, where I go, what I buy etc etc. I don't have anything to hide but my privacy.
I get most of my cash from ATM's every couple of weeks. £200 does me quite nicely.
Oh, and I hate all forms of advertising. It is the work of the devil and I spent 2 years working in the industry.