Ahhh. That's a misconception on your part. There is literally no difference between any kind of sales email, and spam. All sales email to people that haven't opted-in previously, is spam. 100% of it. Thankfully, some countries have even introduced laws against it.
Good point. You've convinced yourself the people you're spamming are in the wrong, and they should trust someone who's already shown to have a distinct lack of ethics.
Literally, by spamming them.
It's absolutely no wonder they're telling you to FOAD, as that's the correct response.
Please, change to a different profession. Preferably one that contributes to society in a positive way instead of your present one. :)
That's the reason for the FOAD response.