With the free to play games on Steam, the two models converge. The advantage for the publishers is, apart from access to the large store window and access to t

With the free to play games on Steam, the two models converge. The advantage for the publishers is, apart from access to the large store window and access to the Steam tools and network for distribution and upgrading, that the micro-transactions become hassle free for the customers, as they all use the same shared Steam Wallet. The advantages for Valve is obviously that they can take a processing fee for the transactions.