"If you walk into a department store, you know the (sales) clerk is a clerk," said Rich Cleland, assistant director in the FTC's division of advertising practices. "Online, if you think that somebody is providing you with independent advice and ... they have an economic motive for what they're saying, that's information a consumer should know."Why should a consumer know that? What does it matter?
If an advertisement or product review functions by persuasion, then it's irrelevant. How persuasive an argument is or isn't does not depend on whether the author was paid.
The FTC has a different model of how consumers shop in mind. In this model, people vouch for products and consumers judge whether to trust them based on their integrity and authority. Reason and persuasion are irrelevant.
I don't think the FTC should monitor whether sources of information are reputable, because I don't think it matters. I have one caveat. If a company pays a blogger to write demonstrably false factual claims about its product, then that's fraud.
I think the FTC sees it this way: when a blogger claims to have integrity (which all product reviews implicitly claim unless they state otherwise), but actually was paid to say stuff and hasn't disclosed this, then that's fraud. It's a demonstrably false factual claim about the author of the product review.
It's a shame how many ideas are judged by their source rather than their content.