[JohnFen]

> By contrast when I signed up for Tesco clubcard, even pre gdpr, I was easily able to opt out of tracking

How do you know they stopped tracking and didn't just stop giving you vouchers and whatnot?

[jsmith99]

Good point. Although I should point out the vouchers would be for their benefit not mine - the whole point of supermarket tracking is to entice you into discovering some high margin item you will end up loving. So their motivation to track is reduced.