You want a game that needed a face behind it to get sales? Painkiller. As soon as Yahtzee did a review on the game, the sales for the game grew, like over 1000%, I want to guestimate reading it was about 3200% increase in sales. And according to wikipedia, not too long after he reviewed in ZP it appeared on the Steam store.
Sometimes you need press like this for a game.
However, using your company to market for a game is a good thing, people buy Valve games all the time because it's Valve, and while yes, the products are quite good always, it doesn't matter because we look at the name.
For games that aren't made by big names who can say "We made this great game so you should buy this other game because we made it," companies should market the game early to reviews. Give them demos and get feedback from them. A lot of us consumers will make decisions on games based on reviews
I bought Saint's Row 2 based on Yahtzee's recommendation and I haven't been disappointed, and I heard about Just Cause 2 from ZP as well. If you want to advertise the game, get some good reviews behind it, and use the reviewers and critics at your disposal to your advantage. Give them a copy of the game, ask them what's good and what's bad, then go fix the bad stuff. Because us consumers are like sheep, we follow orders and take commands from those in power.
If a game is good, it will get the press it needs, but helping it get more will help out a LOT of the time, especially when you can't point out a game and say "We made this" or 'this is the sequel to our great game," because using Just Cause as an example, I hear from EVERYONE that 1 sucked, and about 2? I heard showers of praise for it.