Forums
In the online world the terms "forums" and "messageboards" are used to describe sections of websites where site visitors can ask questions, make comments, help others, and generally find out more about a topic of interest.

Too few businesses make use of forums and have a hard time seeing the payoff for their business.  That's the unfortunate news, because many a business could increase sales substantially by merely having a forum and showing their expertise to site visitors.

One Example
While not a business example, here we have a Bizhand.Com client with a nationwide nonprofit that has the busiest forum on the internet for their area of expertise.  It's helped that organization gain national media attention on a regular and frequent basis and has allowed them to be seen as an "expert" on the issues they represent.  Take that example and apply it to your products, services, or mission and you may begin to see the value of exploring the integration of a forum into your site.