But, ignoring the issue whether most ads are like this or hyper-tuned to psychologically trick you into consuming goods you can't afford, there seems to be another issue here, separate from the parent.
The advertising industry seems to be the biggest pushers of big-data collect-all-you-can-because-you-may-need-it-someday. This automatically erodes privacy for everyone.
For you to have reached that many teachers on such a budget, I assume all this collected data helped immensely, but at what cost?
I'd be interested to hear your thoughts on this.