[TeMPOraL]

Some ads provide a service to the recipient. Most ads, as exist today, provide a net disservice.

I don't think the parent poster meant absolutely all ads, just the vast majority of them. But in so far as they meant all ads, it's still a good point you shouldn't trust them - not even the product catalogs you yourself paid for. There's very little legal and social protection from the merchant lying to you, and all the business incentives to do so.