An individual person’s data is not worth much to anyone (commercially I mean; personal surveillance is a separate matter).
An aggregation of lot of people’s data could be very valuable in certain circumstances.
E.g., if you could identify all the people who were close to being ready to purchase a house, that’s highly valuable to realtors and lenders - but they can still only expect to covert a single digit percentage (or <1%) of that group, so the data is only ever valuable in large aggregated sets.
I've actually run those ads, the aggregated data is worthless. It was almost on average with putting up a billboard, or running ads in the newspaper. Facebook was completely worthless for specifically targeting that example you mentioned. Google...spend a ton of money trying to Target cheap and more expensive keywords. You know what works for real estate.. Call every expired MLS home every morning. Online advertising for real estate is pointless bullshit. Realtor.com, Zillow, Trulia are quite frankly all low quality and insanely expensive for advertising. And yet incredibly innacurate.
If an agent is only converting less than one percent they won't last more than 6 months.
An aggregation of lot of people’s data could be very valuable in certain circumstances.
E.g., if you could identify all the people who were close to being ready to purchase a house, that’s highly valuable to realtors and lenders - but they can still only expect to covert a single digit percentage (or <1%) of that group, so the data is only ever valuable in large aggregated sets.
So the answer is, it depends on a lot of factors.