It doesn’t actually sell data:
“If the goal of Cambridge Analtyica was to show personalized advertisements on Facebook, then what they did was stupid,” Kogan said, arguing that it is much more effective for any advertiser to use Facebook’s own advertising targeting tools.
They allow you to explore data so as to direct advertising programs. Entirely not the same thing at all.
No, really, there’s a difference between “Here’s some data for $” and “Here’s the tools which enable you to target ads, that’ll be $ for the ads please”