@Alexie

I do miss you man, Halo 3 was cool, it was fun playing together.....*sniffs* to bad I converted to the dark side.

Zack and Wiki would be below 20k now without all the great reviews and the hype, and RE4 would be quite lower too. It definitely counts.

Yes, it does. A good example? Lair

This goes both ways however. There are times when reviews will bring to light games which some might have overlooked. They will not change the fate of the game good or bad, but they will push it in the direction it's already going.  This is usually seen in poor reviews much more so than positive reviews.

Okami is an example of a game with great reviews but poor sales. The reviews didn't change the atmosphere surrounding the game to the world itself, but they got a few people interested in it.

Lair is an example of a game where its hype was slaughtered by reviews and sales suffered. Few things could cover up the general disappointment with that title, and reviews only pushed the sales it was going to get down a bit.

Honestly, the best way to suffer least from the effects of reviews is to make a great game. Make a great game, get a great review, and all is usually right with the world. It's when reviewers go sour or games do that problems arise.

Yes reviews matter, conditionally though.

Reviews definately matter more to 'core' gamers than casual. A poor review for a game designed for 'core' gamers will generally doom success (unless it gets good word-of-mouth or strong franchise). However, a great review does not guarantee success but will help launch numbers. Bioshock is a good example of reviews pushing sells.

What reviews cannot do is help a game that is mismatched to it's cliental. IE: Okami/Pyschonauts/Dewy (not that Dewy was well reviewed but it wouldn't have helped)

Casual gamers rely more on word of mouth. This is why MP8 does so well and I believe Mario & Sonic will as well. If they are fun, and can draw attention to themselves, they will sell. Again good reviews will help get more out the door at launch and help this process along, but success isn't imperiled by mediocore reviews like 'core' games are. Let's hope Zach & Wiki benefits from this, although poor MP3 will not (too core).

There is definitely correlation if not causation.

http://vgchartz.com/forum/thread.php?id=4406

To find out, Mr. Schachter and his team reviewed data for more than 1,500 games released from 2002 to 2005, looking for correlations between sales and the games’ scores on Gamerankings.com, which compiles reviews from many publications and Web sites into a numeric verdict between 1 and 100. Their conclusion was simple: Top-rated games sell a lot more copies than bad ones.

...

To conduct apples-to-apples comparisons, I used the scores at Metacritic.com, which pulls together multiple reviews to give media products a score ranging from 1 to 100 that reflects the collective wisdom of professional critics.

The data was clear. The Top 10-selling games of last year — including titles like Gears of War and Guitar Hero 2 —had an average Metacritic score of 87.5. Only one of the top-selling games scored less than 80. (More about that later.) Meanwhile, the Top 10 box-office films of last year — including titles like “Pirates of the Caribbean: Dead Man’s Chest”’ and “X-Men: The Last Stand” — collected a poor average score of 62.9.

I think that the reviews affect initial sales in the first week.

But, after that it is confirmation or non-confirmation from word of mouth...

My example this year is Transformers The Game... It got awful reviews. And did pretty good but not great the first week. But, it kept going after that and had decent legs for a movie game. This is because it is kind of fun... Short, not deep, but fun.

Also, some games get decent reviews but bomb on sales after the first week. Ratchet & Clank looks to be an example. First, week was good... This week well... The great reviews aren't exactly helping spur sales.