Some good counters but I'd counter back with: ...there may be a Facebook group for a niche that is far more active than a dedicated forum site. Two counters f

Some good counters but I'd counter back with: ...there may be a Facebook group for a niche that is far more active than a dedicated forum site. Two counters for this one: 1) Activity is not always what's most valueable. Forums offer value not just in their activity level but in their archives. It's easy to find any post mentioning the word "aerator" for example. You cannot do that easily on Facebook. Besides, Facebook is also used in a more social way than many forums. People post "funny pictures of their cat on their restaurant manual" on Facebook, for example, but they'll ask "Where should I get my restaurant manuals printed?" on a forum. 2) The obvious next question is, "So they'll also search on Facebook for niche groups. How will your list trump FB's up to date results?" It is not just about discovering startup ideas. I think you missed my point completely with this, or so it reads. I'm saying that, for your list to be useful, people have to remember that it exists. No one has to remember that Google or Facebook exists. If they have a problem, bam - off to Google to see if other people have written about it. But where, in the order of when someone thinks "How I will go about finding niche sites" will your list appear? if people find it valuable it is worth the effort But if they don't find it valuable, was it worth the effort? My bookmarks are full of cool lists that I've bookmarked and have big plans to eventually come back and use... May be I didn't made it clear but the objective of this post was to just collect such links not make a wiki on HN. That's a good start, of course. I don't know that I would contribute though. To a certain degree, being able to find this information on your own is sort of a barrier to entry in that market. If you aren't capable of finding quality restaurant forums, for example, then maybe you shouldn't be trying to start a business in that industry. This is a cool idea for a project in which you are learning how to code, or learning a new language, or learning a new stack. It's just not a viable, long-term "thing" IMO for the reasons listed. Prioritization is a big part of entrepreneurship - you have to recognize what's worth doing. You say it takes "a few hours" - no way. Nothing - NOTHING - ever takes however much time you estimate in the software world haha. It will take longer. You will over-optimize in the beginning, start your project, then have to scale back and re-think. It happens to everyone :)