The main difference between a normal server and a dedicated server is that dedicated servers only perform one task, especially when it comes to hosting gaming servers like the Gmod dedicated server, while others do not.

Steam is a DRM, content delivery and multi-player system. A steam dedicated server can be easily setup with the following steps using "HLDS Update Tool":

These steps are not too complicated for those who have experience with gaming servers, and they will be able to do it easily. However, those who want to enjoy the fun of playing Counter-Strike and other multi-player games without really worrying about the technical details, might be interested in steam dedicated server hosting.

So, entering this niche hosting market can be an attractive idea for new web hosts looking for a lucrative vertical market where there is currently little competition.