Drop Parties and Big Rewards. Don't be skimpy, at first! If you want players to stay, give them a good reason!

It's not just about advertising and installing new plugins, you need to improve the gameplay and also give the server the dedication is requires. Nothing goes further than an attentive staff who not only is available, but also listens to their player base. No amount of advertising will get you more players than going the extra mile to make sure you don't just have a server online, but the best on available.

On my server we truly go the distance for our community, we aren't a large server roughly 20 players on each day we peaked at 35 players last Friday, but we value quality over quantity and would much rather have a smaller server but a solid community, rather than a huge server full of immature children and drifters.

FYI Votifier does help a lot since it's a win win scenario for both you and the players. Word of mouth however like many things will be your number 1 source of advertising.

Advertise more? idk =-= im in the same position as you >.> but with less players