Well if you want to spend $4000 (media costs, campaign management, creative, etc.) to acquire a user, I guess. But you can already tailor ads to incredibly spec

Well if you want to spend $4000 (media costs, campaign management, creative, etc.) to acquire a user, I guess. But you can already tailor ads to incredibly specific groups, no need to get to an individual level. For global-size campaigns or political campaigns this level of granularity is needlessly expensive.