@ush,
The forum is the best and most popular communication technique in the seo and other field. we can get many types of the definitions by the from the forum like as,
1. Effective spread-the-word tool
2. It can provide you with highly relevant traffic
3. You build back links
4. You can get a lot of useful ideas from other members
5. It builds your credibility
Here we can discuss our problem and get many helpful solutions by the other members. We can share our ideas for increase business and other type which is useful for user and another person.