Why not? The world is not wholly evil. I know plenty of ads which accurately demonstrate what is good about a product. It seems like you should teach them, "Learn to think for yourself, even if someone says something or believes in something it is not inherently true." But that is a scary thing to teach a child, as an effective teaching of such would invariably lead to them thinking differently than you.

Oh, we certainly tried to teach our kids to think for themselves, too. I believe we were moderately successful. They frequently disagree with me on a whole range of stuff, and nobody finds it scary or threatening.

Nevertheless, I do not believe that any good whatsoever comes from advertising. It is all, without exception, an attempt to propagandize. If nothing else, the underlying agenda is, "Consume, comsume, consume! You don't live up to <impossible image>. You're inadequate and hopeless until you buy <stuff>." Not a healthy message.