As you said to
toomuchtodo, I think you are missing the forest for the trees.
"Ads are a mechanism to overcome information shortages" when honest, but when dishonest they are a mechanism for inferior products to overcome good products and unnecessary products to manipulate people into buying what they don't need.
So what proportion of ads do you think are the former, and what proportion the latter? Maybe you're being honest about your shoes (which still doesn't mean you're right), but what about all the others? What about the big established shoe-makers? So easy for them to claim the same thing, and you won't be able to compete with their large marketing budgets. That's fixed by word-of-mouth? No, you already dismissed that mechanism.
I think most people will agree with me that at least 90% of ads are dishonest on some level. Even if it were only 70%, ads simply replace the information shortage problem with an overwhelming misinformation problem.
The only reason the government needed to spend so much money on advertising the health programs for children is because we've become a society inundated with misinformation (Obama Care is evil!) and news programs that focus on celebrity gossip and missing jetliners instead of truly useful public information (because ratings drive ad revenue). If you can't fight 'em, join 'em. If it weren't for the ad-driven information ecology we have today, there would be much better ways for the government to get that out. For one, it's what the news is supposed to do (as a journalistic duty, not to increase Nielsen ratings/page views to increase ad revenue).
> The reason you're getting downvoted is that "ads are manipulation" requires a "consumer as victim" view of the world. Your view sounds nice to angsty teens, and has a kernel of truth, but fails to hold up to the "anyone who is honest" and 90-99% claims.
If you in your experience (I'm assuming you're not young) don't see that at least 90% of ads (be it for products or political candidates) are misleading at best, then it's unlikely anything I say will convince you.