Don't pay for something that you can be done easily yourself, besides they can't guarantee you anything.
Basically to optimize your site you need to target 2-3 keyword phrases. Put those keywords in your title and description and make sure you use them throughout the text on your content pages and just wait for the SE to pick up your site.
After they do, if you have a detailed stats tracker, It will tell you which keywords surfers are using to find your site. Then you concentrate on those keywords by tweaking (adding more of your keywords) your content page text.
It worked for me , My site
http://www.getnpaid.com moved up from "nowhere to be found" to #2 on Yahoo
Google is a different story however...
Hope this helps
|rasta|