When we talk about Facebook, Google, etc. people commonly believe that "selling data" refers to any, direct or indirect, access third parties gain to the data,

When we talk about Facebook, Google, etc. people commonly believe that "selling data" refers to any, direct or indirect, access third parties gain to the data, as captured by the common phrase of "selling your data to advertisers" used to describe Facebook's practices. So, for most people there is no real, qualitative difference between giving advertisers the ability to use the gathered data to target people with ads on the given platform and (literally) selling that data to advertisers, so that they can target people with ads on a variety of platforms. When companies assert that they are not selling data to third parties, they are using the fuzziness of that term in common usage to imply that the data cannot be used by third parties in any way - which is often not true