I do think there's a reasonable argument for ads, since people don't always know what they could be looking for [1]. Independent magazines can serve a similar purpose, but the difference is between an organization that claims to be unaffiliated with the manufacturer, and needs to be constantly policed to make sure they aren't lying about it, and just being up-front about your affiliation, and only needing to be constantly policed to make sure you aren't lying about the product itself.
Unfortunately, web ads suck. Because there isn't enough Gatekeeping(tm), I can't buy things from web ads, because the probability of it being a scam is too high.