Briefly I will mention that your website models the layout, design, and inspiration of delta.com and delta.org. I will leave it at that as I will assume you have that all worked out.
When "drawing in pilots" it is important to not only get them to join, but get them to stay. By getting a few to stay, they will advocate for you and draw in their friends. I will use my virtual airline Redwood VA as an example. We started off with quite a few applications on opening day about 55. About 40% of them flew, and we continue to give them a reason to fly. Many have advocated and advertised our va through forums, other communities, and social media. We recently hit just over 400 Facebook supporters and we are reaching 80 active pilots.
Make sure to be unique, and to treat your fellow simmers well. You will be rewarded