Internet Marketing consists of several different techniques. As with any type of marketing doing one technique without the others will often give mediocre results. Having no long term plan makes matters even worse.
Search Engine Optimization
The sole purpose of Search Engine Optimization (SEO) is to generate more traffic to your site. Doing SEO consists of two parts we like to call the internal and external part. The internal part consists of optimizing your site enabling Google and the other search engines to read your site correctly. The external part consists of having third party sites link to your site to increase its ranking.
Conversion Optimization consists of making your site as efficient as possible in achieving its goal(s). The goal could be to get a lead or to sell a product and the conversion optimization differs greatly depending on what the goal is.
Bringing It All Together
Taking all these methods and bringing them together in a long term plan brings synergies allowing you to achieve the maximum return on your site. Using all these methods together is very important. To explain it in a different way generating a lot of traffic to your site is useless if the traffic is not used to achieve a goal or if it does a poor job at it. Having a site that is perfectly optimized for conversions is of little use to you also if your site has no traffic.