It is probably not a baseline for what they're selling.
https://www.census.gov/about/history/bureau-history/agency-h...
> Title 13 provides the following protections to individuals and businesses:
> Private information is never published. It is against the law to disclose or publish any private information that identifies an individual or business such, including names, addresses (including GPS coordinates), Social Security Numbers, and telephone numbers.
> The Census Bureau collects information to produce statistics. Personal information cannot be used against respondents by any government agency or court.
> Census Bureau employees are sworn to protect confidentiality. People sworn to uphold Title 13 are legally required to maintain the confidentiality of your data. Every person with access to your data is sworn for life to protect your information and understands that the penalties for violating this law are applicable for a lifetime. Violating the law is a serious federal crime. Anyone who violates this law will face severe penalties, including a federal prison sentence of up to five years, a fine of up to $250,000, or both.
I worked for Data company for a year. We absolutely used Census and ACS as baselines and checks. In fact, there was some talk about getting rid of ACS in Congress and we got emails about "EMAIL YOUR CONGRESSIONAL PERSON, DEMAND ACS STAY. Here are talking points."
I am indeed sworn to not reveal lots of data I knocked on doors for. My memory isn't that good, especially compared to the database it went into, anyway.
I hope it's not a baseline for individual records, but my assumption was that the census data would be pretty useful as a baseline for aggregate information, especially when it comes to comparing to private sets they're working with.