I'd say it's more like, VendorA gives VendorB special buttons (like they kind you pin to your shirt) that promote VendorA, analogous to the "like" buttons.

You visit VendorB for private financial counseling (like an https web session). VendorB is wearing the button during the session.

Unbeknownst to you (and probably VendorB), the button is recording some metadata of your encounter: when you went there, for how long, how loud your voices were, and VendorA periodically scans the button for this data and collects it.

Just like on the web, you were never aware of the implications of the VendorB button, and had no chance to opt out before the recording began.