For me, this isn't specific enough to be appealing.
- What does this "expert community" look like? Is it a web forum? A group of people joining events? A place where people work together? A mailing list?...
- Why is it closed to the public? You're advertising it here, so I'm assuming people won't necessarily know each other.
- How is your community different from any other community? Why do you want to build this in the first place?
Perhaps if you give more details, I'd be able to say whether I'd be interested or not, but this seems too vague to me.