Advertise: You need to advertise good for your server. Not advert something your server don't have. Then players won't come online more and they will not "Advert" more for the server (Most players when they find cool servers tells their friends about the server, because it't boring to play alone and they want someone to play with.) So the best tip is to Advertise the server WELL!

Good staff: Your server will need professional staff. If the players don't like the staff, they will not like the server to. (follow my PMC channel and I will post a blog that tells how to recruit professional staff.)

Plugins: The best is to have self made plugins or uniq plugins. Then the server will be uniq to. And uniq servers are servers that are most popular. But it is only a few peoples that know any plugin devs that want to make plugins for them. So then my tip is to install good popular plugins, learn how to set them up and then set it up right. (I will make a post where you can find the plugins that are popular at this time of the year or something....)

Good spawn: Players love awesome spawns, then they know that it is a good server. (DO NOT STEAL MAPS FROM PMC ETC, if they don't say it's allowed!), but the spawn don't need to be very-awesome, I recommend you to build an awesome simple spawn, where it is easy to get to a place you can build and easy to get where ever you want.

That is all I got today, if you are setting up a server and still want more information about how to get it popular, just message me. I will try to answer as good as possible.

GOOD LUCK!!

-soliderproductions