Search engine optimization and search engine marketing are two different concepts. Search engine marketing is like the actual marketing concept involving paying for the delivery of an advertising message in an attempt to gain customers to make sales or to promote brand awareness. The advertisement effectiveness depends on the figure you want to spend. The profit from an search engine marketing campaign can be analyzed as the money spent, sales achieved, and compare to find out what monetary gain you had. Marketing is typically conducted to promote a service or product that already exists and is immediately available.
Oppositely SEO is not like that. SEO means optimizing a site so that it generates the maximum traffic and ROI. For this your site needs to rank well and SEO helps in doing so. SEO should be implemented when the company is in a position to make the product immediately available. But, SEO is not an easy task. Whatsoever the efforts are made to optimize a site no one can guarantee a number one ranking in any of the search engines. Even if anyone guarantees a number one ranking, the person is a liar.
The following points should be considered for site SEO:
1. Number of unique visitors per day over the last three months
2. Number of pages frequently visited per day over the last three months
3. Position in the organic results for the key terms you want to target in Google, Yahoo, and MSN