Buddy, to be a successful gaming community you need to offer something special. A good server helps, 64 slots running the maps that are most popular. We don't know which those are yet in this new release. Running special events is also a crowd pleaser. Study the server list at odd times of the day, find out if there is some popular servers running in the US that you can replicate their concept (all insurgent or something maybe) and offer to the Euro scene? Recruting some infamous people on the gaming scene to come hangout in the forums also help.
However, there is already a gaming forum re PR so most people here may not feel much interest in going somewhere else in addition to this place.
Get yourself a angle to play off when advertising for people. One recent example is the
Reality Teamwork which is promoting the use of Mumble. They are also hosting the newly started Alliance (a challenge league kinda) in a subforum.
But most of all, read all the forums here in the PR website, learn what has been tried before and what is needed. I doubt many ppl can give you advice on this as many things have been tried already. It is good that you are working to increase the community.
