Here's the thing about sponsored posts: they are NOT authentic. Marketers think that they've discovered the way to customers' hearts and wallets through what Chris Brogan calls the "Everyman." That is, instead of paying actors and copywriters and buying TV spots or print ads, all you have to do is put your product in the hands of Joe or Joanne Regular and let them start the magic word-of-mouth train by blogging/vlogging/tweeting about it. SO much nicer and more genuine than real advertising, right? I mean, which do you trust more--a paid advertisement or a bunch of real people telling you their honest opinions about a product they've already used?
Well, in theory the latter; but only until you start poking around in their collective psyches--or, in this case, blogs. For instance, in a mommy blogger community I recently joined--specifically because I'm curious about this kind of thing--there was a discussion thread "Would you post a poor product review?" Out of 24 responses, only 9 said yes, and of those only 4 were absolute yesses. The rest hemmed and hawed, saying that they don't like to be negative or hurt anyone's feelings or make anyone look bad. One said she had once posted a bad review and the company who supplied the product contacted her and told her to take it down--so she did. The consensus of the thread was pretty much that if you discover you have something negative to say about a product, you should contact the company and see if they still want you to post the review.
Geez, talk about a sure thing. And don't think companies don't know it. They know that people love to get stuff for free--and the bigger/better the thing, the more people want it. And the thing is, they also know that for every person out there with scruples (say the 4 out of the 24 I mention above), there are 20 more who have none.
Not to go back to my blogging/sex analogy, but seriously...say you're a guy looking for sex and willing to pay for it. Would you want a prostitute who makes you feel like a king and fakes it artfully or one who's "authentic" and yawns through the whole thing? If the cost is the same why wouldn't you go for the one who treats you the way you want to be treated? Same for marketers wanting bloggers to generate buzz about their products: if there are millions out there who come right out and say I will not post a negative review because that's not the kind of person I am--of course you're going to send your stuff to those people and not to the ones who say right off the bat that they are 100% honest.