I find it amusing when research groups drone on about this or that, in the end the Marketing groups that are pushing millions of dollars in advertising a month know when so much as a fraction of a point changes in conversion rates, either direction.
Online marketing seems to be very reactionary and any group I've worked with that have managed to stay successful know their numbers VERY well. The only way that too-targeted of ads won't work is if people don't click on it.
The marketing-departments don't give a flying rats ass about privacy, morality or ethics. They ONLY care about what will convert your click to a conversion, and nothing more.
Paying more or less for that marketing data is only useful or valuable to them if you give them your eyes, or money.
For them to coach where a marketing department should put their budget is laughable, and if a marketing group is having to even ask that question, they aren't making their decisions based on performance, they are making it based on assumptions and feelings which will be nothing more than a Fail-Boat marketing campaign, and likely has no clue what they are doing and won't stay/survive in that market long.