I would say steadily network on three. If I were a real estate agent and had to choose three:
1. Localism- The consumer portal of ActiveRain.
2. My own blog- And build a community.
3. Facebook- Yes, by inviting current and past clients and updating on their walls and meeting their friends, etc., you broaden your community, which is what it's all about.
O.K. I will throw in a third- Twitter, because its easy to microblog. It makes sense. Conversations happen, and you can get business from it. Plus you can syndicate twitter to Active Rain, Facebook and your own blog.