87% of the U.S. Population are uniquely identified by {DOB, gender, zip}
While I find this fascinating, I'm sure this is old news to people in the business, like the people that run the  grocery/chain store savings programs.What I'd be really interested to see is why this works, and what it tells us about distribution of population by zip code. I'd imagine the places where this doesn't work as well, are the most densely populated zip codes, where the likely hood of duplicates on the given key increases, but I would never have guessed that the accuracy would be anywhere near 87%. (maybe there's alot more zipcodes than what I thought? maybe they used zip+4?)