You’re welcome to wait for members to stumble upon your community. Sometimes you get lucky. Don’t be surprised if it doesn’t happen though.
If you’re recruiting newcomers, you should target specific people for specific reasons.
This means you’re targeting with specific needs, experience, skills, interests to do participate in a discussion, event or other activity in your community.
A maternity community, for example, might start a discussion about maternity clothes, or create an eBook about maternity clothes. It might target new mothers to give their advice (or offload their clothes). You can find mothers on Twitter, on forums or (if you’re sneaky) by inviting manufacturers to get their customers to participate in the discussion.
Not only do you have a good number of engaged recruits, you also have a good number of advocates for the community once the eBook goes live.
There are numerous variations on this. It doesn’t matter which you use as long as you target specific members for specific reasons (hint: you usually create the reason).