i use ineedhits.com ... ($2.50 per month)
It'll get your name out there in the mix, but I've found that most people don't visit in spite of my site's submission. (Relevancy?)
You could also attempt to use Yahoo's or Google's pay per click, and use the lowest $ amount for the specific keyword you want. forums.digitalpoint.com is a good place to learn stuff, too.
P.S.
if you ever use
http://www.blastengine.com/ (i did once), they have a monthly auto submit for $9.95 per month or something... if you attempt to cancel it, they'll automatically reduce it to $4.95 or $5.95 a month in order to entice you to stay aboard. I left anyhow.
There are some people who wouldn't even recommend submitting your site at all, much less pay for a monthly auto-submit.
It's very hard to build a community for 99% of us.