[teamonkey]

It's easier for publishers to produce multiple, smaller titles. Economies of scale apply to some extent. And they do! But mainly as part of a broad portfolio.

Valve are not typical developer/publishers. They are the gatekeeper, like Apple, Microsoft or Sony. Everything they do is to bring customers in to their walled garden. Their games have effectively infinite budget and can be seen as loss leaders.

Greenlight isn't amazingly helpful for small indies because it requires your game to hit a critical mass of popularity like kickstarter. Unlike kickstarter you need to have already developed the game and have it float about on greenlight for 6mnths+ before you see any return (after Valve's XX% cut of sales).