Putting your server high on the list is a good starter, to do this you
do not put dots... it may look like there are dots at the beginning of the server name but those are infact Euro signs €€€€€€€. The more Euro symbols you put at the beginning of your server name the higher it will be...but being the highest isn't always the best and I would suggest being near the top WITH your clan name/tag still in the name (not just dots) for example
€€€€€€€€€€(JAWA)
Another good way to attract people is to add bots if there are no players, 5-7 bots is a good amount.
Have good admins (depending on which mod you use) so players will come back and you'll get regulars.
Make sure your server is paid for not home hosted... unless you have a separate connection dedicated to your server it won't be a good idea because whenever you download anything from anywhere in your house it will lag the players on your server and no one likes a laggy server. If you do use a home server I'd suggest asking for donations and going to a server provider such as Alchemic Servers (the site is currently being revamped so if you're interested email the manager directly via email)
If you're thinking of playing and no one else is on but bots, still play... this will eventually attract others to play especially in your clan. If your clans gets into the routine of not playing when no one is on then no one will ever play :P.
That's all I can think of right now, hope that helped

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