Buying traffic may not be a long term solution for
most websites.
The key is in creating your own traffic.
Creating traffic to your site is a slow process, but it ain't rocket-science.
Create meaningful links to and from your sites, continue to add content - as much as you possibly can - and the magic happens over time.
Try to get some one-way links. They are precious! FYI, I have a thread at NP at:
http://www.namepros.com/showthread.php?s=&postid=34451#post34451
Get one-way links like that, very selectively, and Google and other search engines will find you over time.
Optimize your site primarily for improved/better end-user experience, and not just the search engines. What is good for the visitors of your site is also good for the search engines. The reverse is usually not true.
Avoid link farms, any short-cuts, and SEO dirty tricks that may result in your site getting a permanent ban from Google, etc., and you wil see the traffic grow over time. The growth is not linear though. It takes a lot of efforts to take off, but once you are air bourne, it's smooth cruising.
Feel free to ask for help in forums like this and other SEO forums. If you keep at it, it will happen!
HTH