It is very simple.. 

Exposure + Content + Time + Niche + Need +  Luck = Members

Then

Members + Friends + Word of Mouth = Low Bounce Rate

I always use craigs list as a perfect example.  No eye candy, even the layout was rough.  But they gave the people what they wanted and fullfilled a need.  That is the key, its not about features and eye candy.  Its about fullfilling a need.   You can have the greatest most expensive, most glamorous, most feature packed site in the world, but if you do not fullfill a need then you are just a bunch of code taking up space.

But best of luck and sell your product.  The days of build it and they will come are over, and have been over for many years. 

Oxwall gives you the kit, you have to build it.. :)

+1 Abbey  not oxwall issue.

Since you dont list your site doman i dont know.  Maybe you need to visit other sites of similar niche and see what they do.   And there is nothing wrong with leaving the house with some business cards and handing them out when you are at social events.  

Spend 75 bucks on a banner (i mean one you can hang on a wall), go to your local club and ask them if you can sponsor an event,  If it costs you $150 bucks or so then no problem put your banner up and make sure they mention you on the mic at last 1x an hour.  It is money well spent.

Remember, people would much rather deal with and be on "freds site"  cause they know fred personally, then they would a site where admin is admin.