Forums are popular place to exchange ideas and comments on a given topic. there are thousands of online forums that can be found on the world wide web. Joining on a forum will not only grant you additional knowledge it will also help on your online marketing needs.
If you are a bitcoin lover or starting out with bitcoin, you should check and visit Bitcointalk.org its a specialized forum for bitcoin and other alternative crypto currency.
Aside from the usual exchanging of ideas and commenting on each other, Bitcointalk.org is a good place to earn while participating in the discussions. Many Companies, Websites and Gambling sites are hiring signature space for advertising purposes. Basically, you can earn some BTC or other ALTcoins on per post basis depending on your account forum rank, the higher the rank the higher the pay. Be wary that spamming is not tolerated on the forum and will lead to account suspension or the worst account termination.