Really and truly the only legitimate way is to have patience. Always keep up with server updates and maintain your plugins. Bumping your Planet Minecraft server post is sure to get you at least 6 - 8 new players in 5 minutes but it's up to them whether or not they stay. Also, slot count doesn't always make the server more appealing.. in my opinion, looking at a server that's 15/25 or 25/45 is a lot more eye-catching than 15/120 or 15/500. Get what I mean? Maybe reduce your slot count to 30 as a start just to give it that full feel when you get players.
Another thing, your domain is whack! mc.play-sword-fac-pvp.com is just so long haha maybe change it to pvp.swordfac.net or mc.swordpvp.com. Not everybody chooses to c/p IPs. Some just memorize it because it's easy to and type it into their server lobby.
Voting is also a critical part in server progression. Voting gets you server score and makes your server go up in the list. Even if it's just a few votes at a time, it all adds up in the end. As a start you can make your voting rewards a little off-set like $10,000 and 24 diamonds for voting on all sites just until you start to get more activate players then you can decrease it.
One last thing, most players like a server that looks well taken care of and has a professional feel to it. They want to join a server that they believe won't die out in a month. Try getting yourself some banners, server logos, making the signs in-game colored and do spell checks on them. Make everything nice and neat.
Hope this helps!
