No, the point is that under GDPR you can't sell personal data because it remains the property of the person it was shared by. You can sell access to that data,

No, the point is that under GDPR you can't sell personal data because it remains the property of the person it was shared by. You can sell access to that data, but the purchaser inherits the terms under which that data was shared and can't use it for any purposes the owner did not already agree to -- plus that transfer itself has to be consensual. Also under GDPR the consent can be revoked at any point and the data has to be deleted. Plus the owner has to be given exhaustive information about what data was gathered, what basis it was gathered on and who it was passed on to (recursively).