I absolutely flat out refuse to pay for traffic for ANY of my sites. My traffic is 100% organic, REAL visitors. How does that happen?
Updating your site regularly with relevant content.
Ping your site AFTER EACH update. Doing this will grab the bots attention so it knows to crawl your site.
NATURAL backlinking on forums (non spamming) and other sites where the members know you and your mannerisms. If they like your stuff, they will follow you.
Apply keywords NATURALLY.
One of the most important things to keep in mind is... You have to give your site time! The first year is when it crawls around in the "Sand Box", and your rank will fluctuate. Your site may not even be seen for a few months.. But you know what? That's ok! Just keep doing what you're doing. It will pay off