Even if it is the former, it would be unusual for a company to use data from their paying customers for other commercial purposes.
Lol what? Not sure if I've misunderstood you here or you are being incredibly naive? Pretty much every big business is monetizing your data, from Coinbase to Coinmarketcap, from Facebook to Google, from your health insurance provider to your streaming content provider.
Not many people pay to use CMC, Facebook, nor Google. I am not sure how you think health insurance companies or Netflex are monetizing customer data.
Netflix makes suggestions based on your viewing history, in part in an effort to get you to use their platform more, but that is hardly "monetizing" data. I am sure that health insurance companies use analytics to try to improve health outcomes, detect fraud, and find efficiencies.