A post from Steve Heimoff yesterday made me think. http://www.steveheimoff.com/index.php/2011/11/14/do-people-like-wines-just-because-the-critics-tell-them-to/
The answer to his question is a resounding yes, of course, maybe even duh! If not, would we see wild swings in popularity and out of stocks for recent high scoring wines? What about the publications and blogs? Anyone who ever bought a wine based on a rating alone has been influenced.
A tasting early in my learning featured a pointed lesson. The teacher of the beginner's class asked us what we smelled in a particular white wine and nodded along with all responses. Finally, he mentioned cassis and, slowly, one head, then two, then all nodded along. He started to laugh, told us we just learned a good lesson and said he didn't smell cassis in the wine but that the power of suggestion from an authority ruled.
The salient point however, is less that critics sway opinions and more about how those critics operate. Most operate ethically but an embarrassing number in authoritative tasting scenarios either do not know enough to inform their audience properly or are not confident enough to admit they do not know an answer.
Taste wines, trust your own palate no matter what anyone else says. If you must listen to pundits, listen to a few different ones and look for consensus or choose one that most closely matches your own palate. That can be discovered through tasting wines rated highly and not so highly by said writer.
I have never observed a money back guarantee on a wine review. Since it's all your cost and risk, make sure to be confident about your palate.