For every niche, there are a wide range of discussion forums online discussing it. All that's needed now is to find the forums that get the lion's share of the traffic in your niche so you can put your plan into motion. That may sound like a very long time, and if so then maybe you believe all the sales letters. Alas, you will have to put more than a little time and effort into it if you really want it to pay off for you. When it's your business on the line, you'll have to decide how to proceed.
Pursuing a particular method of marketing on the Internet is something that you should understand to some degree before you do it. You won't know the benefits of online forum marketing unless you understand its benefits beforehand. Forum marketing is based on networking with other businesses and your niche audience. It's actually more like "relationship marketing", opposed to networking in the traditional sense. The latter is the most important of the two, and it's what you'll use in most other forms of marketing. People like to use forms to build the brand name of their business, something that cannot be done very easily elsewhere. The key is to offer "over the top" value for everything that you have, thus gaining exposure will benefit your brand name immensely. When you are synonymous with value, then your forum reputation will grow.
Don't just comment on existing threads. Start your own threads as well. If you're new to forums or marketing in them, you browse around this site may feel a little shy about starting threads. Just think of a good topic or something worthwhile to share and make a thread. Encourage readers to ask any questions they have too.
If you really want to invite commentary, try saying something that's a little controversial. Of course there's a fine line you don't want to cross by saying something that's irresponsible or judgmental too. Just make sure, above see this page all else, that you start threads that fit with the theme of the forum.
Figure out who has a lot of influence on the forums before you really dig into your own networking efforts. Sometimes there is a group of people that could be at the 'top of the heap' on the forum. The number of active members in a forum will have some influence on this too. Forums with long histories and large memberships will have more influence bringers than smaller forums. The influencing figures are different on different forums. Usually a senior moderator who's been there forever and many people basically try to win favor and acceptance. Once you've identified them, it's time to start building relationship with these members. Forum marketing will boost your company brand, but it will not take place instantly. But even that is not always true because it just depends on the forum and what you're marketing. Some forums allow you to advertise your products or services, and when done right that can bring a fast cash windfall.