In order for you to more effectively convince that person he needed something he did not realize he needed until he saw your advertisement.
I do not know that I have ever seen an ad that aimed to inform without clearly trying to drive the customer towards a conclusion and an action. Even the recent (last 5 years or so?) trend of ads where companies just present wholesome messages or talk about disaster relief or something like that are clearly geared towards appealing to certain segments of the market who will make purchasing decisions under the illusion that those companies are their friends, part of their community, “the good guys”, etc.
One could even argue whether there is a way to produce an ad that is not manipulative, just as one might argue if it is possible to present unbiased news (though there are clearly ways of presenting less biased news). What is and is not said, how it is said, when it is said, what tropes are played to or subverted, and all of the subtle cues… all is aimed not merely to present information but get the consumer to a conclusion and an action. And all have been intensely studied to know just how to get the desired reaction.
One could go even further and say that all communication, even the communication you and I are having right now is manipulative, as we are both seeking to make points, not only with facts, but through conscious and unconscious rhetorical devices, and the use of things like emojis.
Quoting this again, because it reminds me of the analogous idea people have of using “dialogue” to solve problems. Politicians, activists, professors, etc talk about the need for “dialogue”, but you can see clearly that it is just another tool in the tool box for getting what they want.
We’re all here wrestling on this Earth. I am not really trying to demonize manipulation (though the extent of research marketing companies, news organizations, and governments have at their disposal does make it feel more insidious), I just like to be honest about this battlefield.
Of course, stark honesty is itself a tactic, as you probably know.