Louis,
I started and ran a finance website called the Motley Fool UK which has a thriving online community. Many, many people tried to imitate what we had done, particularly the community part, but were unsuccessful because of the head of steam we had built up. It takes a very long time to build up an online community and I'm afraid the competition which pprune provides -- even though it is mainly focused on professional aviation -- makes it a very uphill task, especially if you have no way to drive traffic. By all means try, but be prepared for disappointment.
QDM