According to many website's log, Google counts for 85 % of sales in The Netherlands. Because of this, we only analysis Google's system. The other search engines can actually be ignored.

Google uses 100 parameters to decide a site's ranking on search result page. PageRank is the only variable Google release to public. Not a webmaster can know other variables for sure because Google hide this information by intention. However, there are some factors which are common recognized.

On page optimization

1.Title

Title has the highest weight on the search engine ranking, it is important to have a unique title for each page. One page can only have one or two keywords since search engine only count the first 60 characters of that title
a. Unique title for each page
b. Position of Keyword within Title.

2. URL

Try to use static URL and avoid a URL with long parameters after “?”. Search engine do not deep crawl a site with long parameter because search engine may go into an unlimited loop for those parameters. Those parameters may be a same page with different session id.

3. Meta Tag

Meta keywords are almost ignored by Google. It is not very correct to decide a page content from Meta keywords because Meta keywords can be manipulated by webmaster. Search engine only look at Meta keyword/description when there is no content inside that page or when those Meta keyword/description match the content of that page.

4. Alt text/anchor text

when you have a link, the image alt tag or text inside the link is called Alt text/anchor text. Google take that into account when deciding keyword match.

5. Body text

a. Keyword density. Keyword appears several times inside a page will be helpful for search engine position.
B. Keyword position. The position of keyword inside a page counts as well. The earlier a keyword appears in a page, the more weight it will get.
C. Keyword style. Search engines like Google can read the style of that keyword and take it into account for the ranking. For example, keyword in bold, H1 tag will be helpful as well.

6. Content

Search engine like a page which lots of information/text in it. Content on a page not only increase the chance of keyword match/density. In our experience, search engine also put more weight on a page which more content on it. In my opinion, Google may take content into account when calculating PageRank.

7. link structure

According to Google PageRank' theory, a site's structure influences the distribution of PageRank. JavaScript can be helpful to manipulate the distribution since search engine can not read JavaScript. Google is testing a new bot (Googlebot/test) which is crawling JavaScript file, but we do not see Google use JavaScript yet.

Off page factors

1. PageRank
PageRank is Google's method of measuring a page's "importance." When all other factors such as Title tag and keywords are taken into account, Google uses PageRank to adjust results so that sites that are deemed more "important" will move up in the results page of a user's search accordingly.

2. PageRank is decided by the number and quality of links to a page. In here, quality means the PageRank of that page.

3. PageRank is also a factor which Google use to decide how deep Googlebot will index a site and how often Googlebot will visit a site.

Written by www.submithelper.com