Search Engine Optimization (SEO) is an organic process. Though you can affect your search rankings with pay services, you can and should make every effort to have your site rank well in the natural order of search engines.  Organic SEO is the art of getting a web site to rank optimally well with Google, Yahoo, MSN, and other search engines without attempting to manipulate the system through paid placement services.

You don't have to pay a penny to get ranked. The major search engines clearly detail the technical requirements to fare well in their search rankings. By following their guidelines and structuring your site with SEO in mind from the beginning, you should be able to achieve good rank results.

Be very wary  of SEO companies who promise you placement or guarantee you rankings, say they have priority submissions to a search engine, or indicate they have any sort of special relationship with the search engines. No one can guarantee page rankings, priority submissions do not exist, and google (nor the others) do not develop special relationships with any companies that have any affect on any rankings.

Matt Cutts, Google guru, has been quoted as saying, "Someone walked up to me and pretended like he wanted to bribe me: $500,000 for a 1st place ranking. I turned him down, because no one can guarantee a #1 ranking — not even me.”