If you replace the subject header with "marketing" instead of "advertising" I believe it is more accurate. Today, we are faced with games based upon marketing people who detect certain marketing trends, who assemble games that are "safe" (functional/mediocre) in execution, but supposedly hit on a pile of features people want to play. We have a rehashed list of what is HOT and an industry that wants to capitalize on it. Your game projects need to match up to the hot list. And the hot list ends up being done to death.
You have seen examples this year in Darksiders. Wow... Let's see, 2010 is the year of the Apocalypse (hey, 2012 is almost here), so let's have games themed based on that. And then, let's see... people like God of War, so let's go hack and slash with the War of God. Oh yes, and people like Zelda, so let's create a Zelda world for the War of God to be in.
And then there is an outbreak of tower defense games, and it goes on and on and on. Decisions are being made on what to produce NOT from the gamers but people with money who guess what gamers want, and what has had a "track record". The problem with "track record" is that you produce more of the same and that means a lack of novelty or things that are new that would entertain and surprise.
And as the industry grows, look for more and more marketing first and marketing lead, to drive up production costs and pure bland mediocrity (because they MUST sell) are put out, until a number of publishers will collapse under the weight of their own hubris (and bloated budgets).