The main difference is that, the 'good' server hosts that you pay for run industry standard hardware as opposed to a personal use computer. These machines are designed solely to host a server for a game (in this case, Minecraft). The maintenance for these machines as well as troubleshooting help is all provided by the server hosts in exchange for paying for the server.
The major difference is, if you try to host a server off of the computer you're also playing Minecraft on, you're going to be affecting the performance of both the server and your own game. Whilst it's bearable to play lag on your own personal game, the server lagging (performance, not internet-wise) will affect every player coming onto the server.
Whilst hosting a personal server for free off of your own machine is fine for a LAN or for you and a few friends to play on over the net is fine. Hosting a 150 slot server that constantly has over 100 people playing per day will have a huge impact on your computers processing speed and you will be unable to play or even use your PC without affecting the server.
Another major reason people 'buy' servers is due to internet speeds, I myself have terrible internet and don't live anywhere near the majority of players that hit my server, so hosting one of a personal machine would be pointless and provide a terrible experience for all. Instead I pay for mine to be hosted closer to the majority of players and we all have a better time as a result.
The final major reason is run-time. Basically everyone wants a server they can jump onto at any hour regardless of if the owner is on or not. While you could leave your computer on ALL the time and keep a 24/7 server running, sooner or later you will want your computer's processing power back so that you can do your own thing or play a different game. Whereas if you pay for a host, the server will constantly be running without you having to turn it off because you feel like playing something else that wouldn't run with a server side by side.
In my own personal experience, having hosted both a personal server and a paid server, I would recommend a paid server if you wish to have a dedicated 24/7 server that ANYONE can join. However if it's just for when your mates come round to have a LAN and then only for you guys when you feel like it over the net, continue with a free, self hosted server.
Thanks for taking the time to read.
- Snozzlebot
Owner of the OfficeRiot Forums SMP
