May I ask what type of a site you are working with? It also depends on your budget of course.

As a side note, I would strongly discourage you from doing anything that has to do with any sort of...

No problem.

If you want to buy traffic for your site, well, I'd go with Google Adwords. You can definitely buy some traffic there.

You can try looking at www.salesgenie.com (i think thats the URL). I believe you get a good amount of leads for $250/month.