Steam

WON was a multiplayer service that was ALSO a early foray into online game distribution. Somewhat ironically as the platform on which Valve's Half-life was originally published.

The modern era of online games distribution is pretty closely tied to multiplayer hosting because those were the games that were primarily targeted for online distribution in a world where MOST games were offline and physically distributed.

Steam launched its own platform to compete with WON and moved all of its own titles over there. The biggest controversy associated with that was that Valve sent out a patch over the WON servers to move all the existing WON enabled games over to the new Steam platform.