A new study shows that, when asked, people do not like tailored ads, because of privacy concerns.
From the abstract:

Contrary to what many marketers claim, most adult Americans (66%) do not want marketers to tailor advertisements to their interests. Moreover, when Americans are informed of three common ways that marketers gather data about people in order to tailor ads, even higher percentages - between 73% and 86% - say they would not want such advertising. Even among young adults, whom advertisers often portray as caring little about information privacy, more than half (55%) of 18-24 years-old do not want tailored advertising. And contrary to consistent assertions of marketers, young adults have as strong an aversion to being followed across websites and offline (for example, in stores) as do older adults.

I'm not sure what such studies are worth. For decades now, people say, when asked, that they are worried about privacy, but do nothing to protect it. On the contrary. It's called the "privacy paradox" and indicates that the question is, perhaps, wrong.