I personally don't run a server but here is a few tips to help you out.
1. Make your spawn interesting
It sounds like you already have that, but a box with signs will not attract people.
2. Have a set goal for your server
If you want a survival server, make sure to tell your server that
3. Have non money ranks
They don't have to give the player a perk, but a rank were you have to build something amazing to get the rank is a good idea. It gives the player something to work for.
4. Plugins
Have many plugins on your server. For survival I recommend towny but the choice is yours
Mini game server tips:
1. Have a point system
Players want a reward when they play for awhile. Maybe give a hunger games player a stone axe when the start
2. Be creative with spawn (this goes with all servers)
Most minecraft multiplayers have seen the hive, super craft bros, and mineplex spawns. Do something creative, and new
Survival/creative server tips
1. A market/store
All survival servers in praticular need a market. It gives the players A. A place to buy stuff they need and B. A place to earn money. Selling a diamond could give you a 1000 dollars or something like that
2. A currency
Whether it dollars, euros, or some made up currency, use a currency plugin so you can keep track of your money. Currency works really well with towny.
Finally, the most important rule for servers is staff. Even if you have a great spawn, survival world, and 10 mini games, you need an active staff. Nobody will get on your server if a player can grief and get away with it. Have a grief command, were a staff comes ASAP to the scene.as to your staff question, tell the they have to work for it. It makes them stay on because they want the position but doesn't give a griefer a staff position.
