Nano Targeting - How Many Interest Do I Need to Know From My User?

As low as four data points are enough to identify one user in a database of one million users. We found out examples, not academic work, like a sample of people that have tried to use this system for sending love messages. The more I know from you, the more efficient can be my marketing campaign. There are a lot of campaigns that target less than 100, 300 is supposed to be an agreed-upon limit. So there's no reason why we shouldn't make it even lower.