yes you're right guys but there's so many general directories out there and competition is rude. I think local directories are a good try, why not, If you live in a big town and have a business directory set especially for it. Just thoughts
Why would a niche link directory need to be promoted to general web users?. It really doesn't matter if it get consumer traffic all that matters it that it gets listing traffic. Heck, if you sold the links separately they wouldn't even need to get the the site
The deeper the niche the better quality the traffic and easier it will be to move up the search engine rankings. But the downside is that the more focused the niche the less traffic you will get. Make sure if you have a narrow niche that is geographically wide. ie nationwide or whole world.
There are just so many directories out there that unless you're offering something unique you'll likely need very deep pockets to really get it off the ground.