Three major things. I won't be sugar coating this.
1. Increase your social media impact. Twitter is nice but there are so many other sites you could be using, and if you are using other sites like Facebook, Tumblr, Reddit you need to push them more because I have never seen them. I should know from the second I visit the home page that you have social media plugs. This was actually a major problem when the game and site were down because people just couldn't get information. Tell people to check the twitter for status updates and they'd be dumbfounded to the idea that the site had any social media plugs.
2. Vote page site spinner. SoulSplit has this one pat down and we're really getting punched down by not having one. Unless they're massively dedicated members won't click a dozens links in a thread they have to find on the forums whenever they want to vote (if they want to vote). Users should be able to type ::vote when they login to the game and have a browser window popup with the previously mentioned site spinner, simple and easy. Also a login message reminding members to support you by voting, possible with a timer to tell you when you can vote again (i.e. every 12 hours) couldn't hurt.
While no in game ranks or items should be given for voting you should still give people something, perhaps a forums rank for voting a certain number of times (10, 20, ect) along with a counter on the users profile for how many times they've voted. If there's anything any of us have learned from years of playing RS it's that people will slave themselves to death to earn pointless pixels on a screen.
3. The highscores. People like to brag, it mainly is the motivator to play these games in a "no life" fashion if we're all going to be honest here. Since we most likely will not see the addition of skillcapes to the game we need a place that members can show off other than the forums. There's not much more to be said on that topic.
Without the three of these the game will be permanently growth stunted. The fact that another server's word can be taken higher than ours is a sign that things need a PR rework.