Movie reviews don't always carry that much weight in the film industry. Maybe that's because reading a review isn't really necessary to get a fairly good idea of what it will be like (trailers give away too much as it is these days). Plus, I normally don't put too much thought into whether or not to see a movie. If it's a superhero movie, for example, I'm there (yes, even the sure-to-be-awful Fantastic Four sequel). Or maybe I'll end up seeing some movie just because my friends are going. With games, however, reviews are HUGE.
Buying a game feels like an investment, even if it's not much more than New York round-trip cab fare from my apartment to SoHo. You can't buy a game with friends, because only one of you gets to take it home, and nobody wants to share 1/4 of a great game. Games are also more of a long-term entertainment purchase. You can go see a movie and get your fill from 90 minutes of action. In a game, you (hopefully) spend more time to get the whole experience, making it much more difficult to tell from a trailer or poster whether the game will be good. In fact, reading reviews for a lot of gamers is just part of the buying process. For example, there are several huge gaming magazines and websites that provide reviews to gamers hungry for editorial opinions. When was the last time that you picked up a magazine (or subscribed to one, for that matter) that basically just previewed and reviewed movies?
We should be thankful for the importance of reviews in the game industry. This can help to counter-balance issues like small-budget games getting no attention (see Katamari Damacy as an example of game-saved-by-review). Our industry is fortunate (or unfortunate for the makers of most Barbie games) to have an economy so heavily reliant upon informed purchases. Parents, if they put more energy into their kids than they did into 8th-grade Pre-Calculus, should see that this is also invaluable to them. Need more than just the ESRB rating to judge whether a game is right for your kid? You have countless reviews and gameplay videos at your disposal to make said judgement. I found this especially useful when buying games for my little cousin recently.
Our review-heavy culture spawns, I think, more informed buyers than the movie or music industry, which runs on the "Carson Daily/Ryan Seacrest told me to" purchase model. I encourage all gamers to show their support of this system by making an effort to make informed purchases. When you ignorantly buy Killman's Wild Beach-Tank Adventure 7: Race to the Party Zone, you not only flush your money down the GameStop toilet, you inadvertently support the publisher and developer that let it see the light of day. Hey, friends don't let friends by crappy games. Spread the word.