Know-How Exchange : E-Marketing

To get things started two ideas come to mind:
1. Email campaign from a rented/purchased list to prime the pump. Make sure they land on a page that really sells the benefits.
2. Purchase advertising space in trade publications that already targets your audience. Consider a sub-domain or special page so you can have them land on page that fits your audience and their needs.

I am assuming that our portal will not become their home page so it is imperative you get them to sign up for a newsletter so that you can send out announcements to them when new relevant information becomes available.

As this list grows, you begin a viral campaign, which would reward them for getting their friends and colleges also to come to the site.