If it helps to understand the power and role of marketing stories, think of them in this way:
Platforms (PC, Steam, Facebook, iPhone, Wii, board gamers, roleplayers - think loosely) are like countries. Players are members of the country, understand the country's rules and play within its borders. They may be aware of other countries, but their on-the-ground awareness of them is often shallow. Only a few especially motivated gamers are true internationals, and even they often have a favoured platform or two where they spend most of their time.
Marketing stories are like religions. They are the causes, memes and ideas that matter. Some go across many platforms, but many don't. Stories that motivate Steam players are unintelligible nonsense to Facebook players, and vice versa. Although the processes of many platforms seems similar (much as the laws in many countries are), it's the people and why they are there which is different. Values and identity are different. Customs are different.
It's very important to figure out whether your chosen country has the religion you want to tap into. Many don't, even if they seem like they should. There is no Facebook indie audience, for example, even though it seems like there could be. There is no audience for streamed cloud gaming like Onlive, even with all the funding, technology and strategy documents in the world. Nobody cares.
It's especially important to understand this now: The platform rush of the last five years is basically over, and even the new platforms (Windows 8, for instance) are likely to fill very quickly with the same content as you see on other platforms. The next phase is the marketing story phase, and the renaissances and reformations that go with them.
Though you may not realise it yet, you're basically in the church business.