[gabriel34]

Correlation will hold between unique hashes and unique visitors to access increase in unique visitors for your campaign. Even the percentage of these accesses that are returning is likely constant. All you would be giving up is the ability to measure variation in the returning percentage across several days (even so you could probably modify the code to change the salt every x days without losing much of the privacy benefits)

There will always be value to be extracted from the invasion of your users' privacy, but you also hit diminishing returns over this increasingly invasive probing. Plausible is aiming for "good enough" whilst respecting people's privacy, and that is a good compromise IMHO.

There is a trade-off. You will never get 100% of the information without all the tracking, but there is information that represents more bang for the privacy buck.

Would you not have a acceptable error increase in your decisions with a bit less information and a lot less privacy invasion?

EDIT> I think more control to the user is better, so instead of canvas fingerprinting, shady cross-site tracking and all, I would rather have a uuid that my browser informed, but that I controlled, so I could be anonymous when I want to and be tracked when I don't care, or when I genuinely agrees it adds value.