Yeah i know it isn't THAT simple. A sequel has already loads of advertising and image under it and yada yada yada and consumers work in the games world similar to how they work with every other brand or product that are sold for us. It's a good thing that the most vocal people aren't the average joes, but the Joe Behaving responsibly. But then again, the average joe has more force and more spontaneous actions and behave like drones attacking everything defined evil in their programming.
Anway, if having in-game advertising for example in a game has negative effect for sales and mr reviewer says that this is the one thing that really sucks about this game, they will reduce it. If NHL 200X drops sales compared to the previous one and mr reviewer says it's not new enough, they will work to make something new next time. That's what i mean and now that i look at i'd change the "more sequels" to "bad sequels". Small things affect sales...ridicilously small, it's all in the numbers. If feature XY makes people like the game 1% less, that will show in sales. If some feature is big and bad enough to have people start spreading the bad buzz about it, that feature will be less likely used by others. Some series have had a constant decline in sales just due to the fact that you can't constantly sell sequels in the same series for same people, they will get tired and stop buying the games, they don't have to snap out of it. When this happens they refurbish the series(like Megaman / Megaman X / Megaman ZX / Megaman Legends /Megaman EXE / Megaman Starforce, which are standalone series, but way different from each other luckily still gaining momentum from the megaman brand) or start making another one.
But why should the joe be helped? People like having strong image for their products and enjoy it. I like the associations coming with the transformers toys on my table. The marketing totally droned me, but i don't mind. They're cool on their own, but even better with moar mental images.. i really feel like going to buy a yellow camaro with black racing stripes and putting the autobot logo on the steering wheel. If i see a transforming robot toy in the store and it's not Transformers, i'll instantly go "That's totally shit, it's not transformers"
I didn't mean to say that people need to make more responsible choices, since whatever rocks their boat is just fine with me, but that their choices determine things regardless.