Motocross635

Ok so, I run a minecraft server and I have been doing that for more than one and a half year. I am happy with my server mostly, but I have an issue. I just can't get players to come, and stay at my server. And I really, honestly, have no idea why. We're running on a dedicated server and there should be no lagg at all. 1 gbps uplink connection. Shouldn't be any issues? The spawn is looking good enough, but we're working on a new one, which looks great. We're bumping on planetminecraft almost everyday and we're advertising on minecraftservers.org and some other too. If you want to help or check the server out, please look at the ip: mc.zeuby.org. We're hosted in germany. Both of the owners (Me and another dude) know java coding and we have a unique gaming server hubbed in this. Still, no players. This does get alot of people to play it, but only for a short while, because than they leave and there's noone to play with. This makes that server kinda empty / boring. So the other owner coded a zombie survival which works without other people, still this doesn't seem to attract many more. PLEASE HELP ME! I'm raging. I just want 1 and a half year of my life not to be wasted. I appreciate any kind of feed back. Even if it would require me to work hard. Thanks and please reply ASAP. Regards Sad owner of Zeuby, Motocross635. :'(