You'l have a much easier time succeeding if you have money and contacts before you start. Not usually the case though, some really good advice here, one thing I'd add that has worked for me is having a lot of unique images within my content, it seems to get me a lot of hits from google images on top of my normal impressions =P
SEO your pages. Guest posting and blog comments. Write good, thorough articles on discussion forums such as Digital Points to generate backlinks, and don't ignore your social media. I also found this article to be pretty helpful: http://www.technshare.com/best-marketing-tips/
Probably the most important thing is that you need to put in relevant content in each of the pages of your websites. Everything must be important to what you are trying to sell and must in its own way contribute to convincing customers of the worth of your services. This is why you must be vigilant with the qualiy control for the content of your sites. After all, one bad page can effectively cut down the amount of traffic that your site will get. Relevant content will let you keep traffic coming to yourself, and any other tips and tricks will be the ones to increase the traffic.
Buying an opt-in list? from where? And are you sure that, buying an email lists is comply with CAN-SPAM act?
See these are methods people pay to get, I've used these on most of my blogs and i get a pretty good amount of traffic well written.