We know how skewed the distribution of wealth and income are. But I suspect that if you had data about the flux of advertising dollars you would discover that those dollars are targeted disproportionately at tail of the distribution.
I gather that it is well known that if you look at the ads in a given newspaper of magazine the ads are targeted toward the high end of their readership. Hence the ads for thousand dollar watches in the New York Times.
Possibly selling into the high end of the distribution is so lucrative that you don’t really use advertising as most of us think of it. The selling channels are different; you give talks at Ted and get booth space at the superbowl.
Which makes me wonder how different the ads are if my IP address is in 10028 (Upper East Side of Manhattan, avg income $227K/year) v.s. 10454 (South Bronx, avg. income $18K/year). There must be advertisers who have figured that out.