It's certainly true that you have to give before you get. In an online community where you can't give free food and drinks, you still have to provide some offering of value. In my opinion, providing professional content is one of the best ways businesses can offer value to their community. I say "professional" because it's not just user-generated content, but content provided by the brand. Find out what your customers are interested in and how those interests are relevant to your brand - much like the plumber example. Offer that valuable content to your community and you provide a strong incentive for your customers to show up, discuss, and establish strong long-term relationships with your brand.

That's pretty funny. Now I don't feel as bad about my family learning about my engagement via my "he put a ring on it" Facebook update. Heh.