You’d be surprised how bad/incomplete the data usually is and how much work it takes to make those datasets really useful or reliable. That’s one reason Xoom I

You’d be surprised how bad/incomplete the data usually is and how much work it takes to make those datasets really useful or reliable. That’s one reason Xoom Info was able to sell for a billion dollars and even their data has a lot of junk Having well curated detailed census data would be a major boon for the data brokers