If advertising and public relations were absolutely effective, we would all be mindless zombie slaves, and no one would be questioning the role of advertising in our lives. Yet if they were completely worthless, it seems unlikely that anyone would pay for them.
Some advertising consists of informing consumers about their options. No problem there.
Some advertising is intended to increase the market for an item. When the producer genuinely believes that a good improves the lives of consumers, again no problem. (Or must an ethical producer do research to assure that this is so, and not just a convenient belief?) If the producer has no such belief, what does ethics demand? Some goods are fun but frivolous, others are compelling yet dangerous. If congress legalized drugs, how would I react to an ad for heroin?