If you ever found yourself wondering whether all of the various publisher-exclusive storefronts have had a significant impact on Steam's success, it would appear that the answer is yes. The reason I say this is because Valve has just announced that they have implemented significantly better revenue sharing tiers for highly successful games.
So instead of the 70%/30% split that has been standard across Steam since its inception, the new revenue tiers will be 75%/25% for games that have earned more than $10M, and 80%/20% for games that have managed to garner more than $50M. As for what exactly "revenue" includes, Valve has clarified that it's a combination of game sales, package sales, in-game sales, and even Community Marketplace fees.
This is most likely not going to have much of an impact for the vast majority of developers on Steam, but there is a chance it might attract some of the big publishers to once again start releasing their games on Steam. While I don't particularly care how much profit giant companies will manage to garner out of deals like this, I am always happy to see more competition between the various storefronts. After all, we as the customers can only benefit from such things!
To learn a little bit more about Steam's new changes, as well as Valve's reasoning behind them, you should head on over to the announcement post.