My GP clinic uses Manage My Health. About to log in and they say I need to accept their new privacy policy. So I just read their privacy policy (https://www.managemyhealth.co.nz/privacy-policy/), resulting in the following message from me to them:

Hi
I have some questions about your privacy policy.
In 3.e you say you use personal information for advertising.
As you must surely know, online advertising is a privacy nightmare because of widespread use of tracking technology and abuses by companies domiciled in places with poor privacy practices. Technologies such as browser fingerprinting mean that even with adblockers and refusing cookies, it is impossible to stop identity matching by (eg) Google, Facebook, and even less ethical companies.
Do you use 3rd party ad and tracking providers? If yes, then this is a deal-breaker for me in a medical service.
My concern is particularly aroused by reading this provision in conjunction with  s4.1.a, where you say you may disclose personal information to a related company who may use it for the same purposes.
How do you define "related company?"
I look forward to hearing how your service does or does not use 3rd party tracking and advertising services so I can make an informed decision.
Thanks
Stephen