Yeah you're right, Steam does offer a lot more than just file hosting. They also do DRM, friends lists, games promotions, and modding marketplaces, although each of these things certainly also have cheaper/decentralized solutions.
The 30% number is one that they might start to get pressure on with competition. GOG now pulls something like 10% of steam sales on the games they curate (citation needed) and I believe they are working on a stronger community/online platform.
There are also more indie upstarts like http://itch.io, which are smaller but focus on developer outreach and close-knit community.
The 30% number is one that they might start to get pressure on with competition. GOG now pulls something like 10% of steam sales on the games they curate (citation needed) and I believe they are working on a stronger community/online platform.
There are also more indie upstarts like http://itch.io, which are smaller but focus on developer outreach and close-knit community.