The danger of manipulation through propaganda is indeed an argument used in political discourse, though in reasonable discussions when talking about direct and

The danger of manipulation through propaganda is indeed an argument used in political discourse, though in reasonable discussions when talking about direct and indirect democracy. The layers of parliamentary systems are partly a means of protection against manipulations. If you want to read an interesting and nice to read book that partly talks about this, then I'd recommend Profiles in Courage by John F. Kennedy. Though a consumer decision is not the same as a political vote, at least the latter is not supposed to be similarly thoughtless, so there is no need to interpret my comment that broadly.