Is it really such an odd question? Putting advertising outside, it seems to me that it would be a common occurrence that someone dealing with problem X has probably spoken to other people with the same issue, and what the group knows works well would be spread around. In my case, I'm asthmatic, and I know very well what works best for me, simply because I've had decades of experience figuring it out. When I've gone to see a new doctor, I've been specific in my medicine requests, and it has been received well enough.