Snake oil salespersons can sell to companies as well.
Seing how massively even Google have mistargeted me and lots and lots of others I'm even sure it is a fluke anymore:
AFAIK Google sells ads not by the click anymore but by the impression. Now, how do you maximize revenue? You show the most expensive ad to as many people as possible.
A little (ok, a lot) of fudging here and there and I am a target demographic for shady dating sites / mail order brides / senior dating / gay cruises for 13 consecutive years.
Was it ever relevant to me? No way. I even repeatedly reported those ads.
Does relevant ads exist? As Facebook has proven a few times: yes.
It's hard to believe the economy is dumping almost 100B/year into a product that doesn't work.