This point of view is a bit ahistorical. Madison Avenue's success during the latter part of the 20th century (and still today) lies in exactly producing 'vanilla' people, with brand new 'vanilla' insecurities, that broadcast media can then target to sell them mass produced 'solutions'.

However, I still find the prospect of advertisers doing so more efficiently at scale in today's fragmented media environment (which has been making things more difficult for them for a while) rather disturbing.

Incidentally, this sort of manipulative A/B experiment is a key element of a plot point at the beginning of Vernor Vinge's 'Rainbows End': http://en.wikipedia.org/wiki/Rainbows_End

Or A/B testing. Show only depressing stuff to some people, and nice stuff to all their friends, to see how they deal with the disconnect.

The potential is limitless.