There are thousands of forums on the internet today. Traffic levels range from a few people per day to millions per day. Topics for these forums range from "online money making", to "People traveling to Cambodia". So, how can you choose a niche for your forum that is not too competitive? Here is a step by step guide:
#1 Search for New Stuff
As vague as this heading is, it's the most important. You need to stay on top of news feeds about subjects that interest you. If you are a video game geek, then stay tuned every day, every hour to the latest breaking news from the video game world.
#2 When you find a breaking news story related to your Subject, Act Immediately!
OK, so say you were watching the various video game news feeds and see that a new game was just announced. Do you feel this game will be popular? If so, there you go, you have your new niche for a forum. Because you are acting fast, before anyone else, you can quickly get started on beating everyone else to the punch
#3 Take Action
Buy a solid domain name related to this new niche you found, create a forum on the domain, and begin slowly promoting it. You have just planted the seeds for your niche forum to grow along with the game's (the niche itself's) popularity.
#4 Stay on top
Since you were the first to create a forum around "Game XYZ," it will be much easier for you to dominate this niche. Because forums require traffic to stay on top, the fact that your forum will be the first about this niche and have more traffic then any forum started after yours, you have a tremendous head start on the competition. All you have to do now, is post at your forum with updates, news, and information that the members will find useful, and promote your forum, trying to get back links.
If you quickly enter a niche for a forum before the competition does, you will have the head start needed to eventually grow with, and dominate this niche. Later you can place ads on your forum and sell products as an affiliate related to this niche.