All of the above mentioned ways are great, so I wanted to ad VIRAL traffic builders. My personal favorite is vTrafficRush.com because your banner ad can be seen by 6 levels, potentially tens of thousands of people or more. You just ad your banner ad and promote your vTrafficRush affiliate link to start the viral effect.
More than just Viral Traffic sites like vTrafficRush and FreeViral I prefer viral referral traffic exchanges like easyHits4U that allow you to get all referrals and their referrals down several levels to earn you traffic every month. Build a strong network in these type exchanges and instead of a visitor being to your site once you will have them there hundreds or even thousands of times increasing your conversions. The secret is offer the viewer a means to increase their traffic in exchange for their e-mail address.