An Interactive Forum is an open discussion place on your website. You control the discussion topics, and visitors can comment, ask questions about and even debate the topic. It is a great place to handle questions, compare products and services, and build an open relationship with many of your visitors. Interactive Forums add a lot of content to your website without you having to do all of the work. Search Engines love them. For your visitors, a good, active forum can be quite addictive.
For the business owner, they take a bit to get going, but once your customers and visitors get hooked, they are the best thing to add content and stay on the top of the search engines. Think of it as having a big relaxing living room in the middle of your business where you intentionally invite visitors and customers to come in and relax. As they arrive, you hand them a list of discussion topics. 
They have fun, they like being involved and engaged, and you get good information and feedback. Since it is on-line, you can control what stays up on your site and gets seen by future visitors with minimal monitoring. Forums only help you with the search engines if they are hosted as an internal part of your website and are NOT a third-party discussion board hosted outside your website. That is why businesses who rely on things like Facebook for their forums don’t do a lot to draw traffic to their websites. The goal is to draw them out of Facebook and into your own private forum.
Another way businesses and companies are using forums is to provide customer service and support. A business can create forum categories and forums that would help their customers user their products more effectively and help them troubleshoot any issues they may have without having to wait long periods of time on the telephone on hold or navigating through difficult phone systems to get the answers they need. Visitors can read through the forum post that other visitors have left that could help them with their issue, question or concern.