The nature of online political forums is such that they tend to attract two major types of contributors.
The first type of contributors you are likely to find in web-based political forums is that of contributors who are paid to start threads or contribute to threads on the forums. Some of these are paid by the politicians, to manage their messaging on the message boards (especially keeping in mind that some web-based political forums tend to be so influential). Others are paid by the owners of the forums, to ‘populate’ the forums. This is essentially a web content development undertaking, as it is understood that the forum pages can then be monetized just like blogs (say, through pay per click advertising), giving a revenue stream to the owners.
The second type of contributors you are likely to find in web-based political forums is that of contributors who are not paid: contributors who make contributions based on their own convictions. These tend to be diehard supporters of certain politicians or certain political thoughts. Since they are not paid, they tend to have limited time for posting: though we have had cases of people who spend practically all their free time on these types of forums: posting and responding to messages.