Often it's even more blatant than that. We were approached by a cable TV 'review' show and they were really 'excited about CQC' and wanted to do a review on it. That sounded great to me, what's involved? Well, you pay us $30K and we will be excited about your product on our show for give minutes. I'm condensing the conversation of course, but not a lot. Basically they would do three or four products per weekly show (or maybe it was bi-weekly), and raise $100K or so, and that's how the show makes its money. It's a straight out fee for them to pimp your product, but to act like it's just some product they found and really like. I imagine, had it gone forward, we'd have written most of the text for it as well, since I doubt they'd have taken the time to actually learn anything about the product. How could they with four of them a week being pimped?
In that kind of scheme, they don't even have to care if the product sells or not. They get paid either way, just as though it were a straight advertisement.
I imagine on the web those sites are also using their hits to sell web ads for folks like Google and whatnot. As long as you hit their site, it doesn't matter whether it helps or if you read anything.