If you can target by age, wealth, region, interests, etc. Can you target by gullibility or vulnerability?
I am sure these companies have figured it out. Maybe mental/disease issues like Down Syndrome, Alcoholism, or gambling addiction. Perhaps age deterioration where general acuity is lessened or dementia. Teens more susceptible to peer pressure.
I am sure there are a lot of other possibilities. Curious if these are actual segments that can be targeted, directly or indirectly?
(no I don't want to target them)
This, of course, assumes that the input data has a strong enough signal to predict (or describe) gullibility, which may or may not be true depending on the data you have available.
Data scientists model personality characteristics like gullibility in domains such as message testing (advertising) and persuasion modeling (political elections).