The world, in my case, usually tends to serve the story - I don't go around making worlds for the sake of it, simply because it isn't the way I write. With the exception of my in-progress novel, which does have the weight of a whole alternate Earth behind it, I always focus on local milieu rather than wider storyworld, and then, if sequels require it, I bring more of the flavorful details out.

Then again, I tend to work with evocative names rather than concrete numbers, so please take my advice with a large lump of rock-salt. I don't even know what I'm on about half the time. :)