I feel like you're arguing that dirt is worth as much as the farm that one could build with it.
For example, that 40cpm is to reach a pool of <1000 users who are in charge of purchasing for networks of hospitals, and my ads are for MRI machines. 3rd party data is unbelievably valuable, probably $1.5 million of my budget goes to data costs alone.
This is well understood by the adtech community and even the flashy new "ABM" companies will tell you the same. 3rd party data is universally terrible. At best, it'll work at scale (of millions) on general demographic details but will definitely not recognize 1000 people on the open web.
That kind of list might work on Linkedin or Facebook with email targeting but it would be easier to focus on niche trade sites without any data, or just use a direct sales team. That $1.5M in data you're paying for would have much better ROI with a good VP of sales.
Sometimes you can prod your potential customers into action.
If someone tried to do that to me, I’d report the attempt to the company lawyer, and I’d doubt the quality of the thing they were selling was as good as the quality of the thing the other poster was advertising.