I wholeheartedly disagree. What about the case where the person involved actually loves the product and wanted to talk about it anyway? This is frequently the case with gamers, models that prefer certain makeup, etc. What's worth doing is worth getting paid for, but that doesn't necessarily mean they "intend to deceive" - in fact it's the exact opposite. It's an honest endorsement.
IMO, it should only be required to be labeled as an ad if the post wouldn't have been made unless the brand paid for it.