Not necessarily, they might have timestamps and register # that could be correlated to build a "unsupervised" profile of a customer. Extreme case: you are the

Not necessarily, they might have timestamps and register # that could be correlated to build a "unsupervised" profile of a customer. Extreme case: you are the only person that ever buys product X around time Y, so that fact can be used as an anchor to build a profile. You need to be way more paranoid if you want to be a true privacy warrior.