2.1.: Popularity vs. projected market share

It has been said several times by several people doing Market Research on the Internet but cannot be stressed enough. Popularity of a keyword doesn't mean a lot of money in the topic. Doing search engine optimization should be about optimizing an already established or soon to be established online presence that would fill in a gap in information / products / services provided over the Internet, and wants to be present on the Search Engine result pages. And not solely aimed at filling in gaps in Search Engine result pages. User behavior shows that people are being more and more cautious about where they spend money on the Internet, and whether they should trust an enterprise based solely on its online presence. Most queries are still made for informative and entertainment purposes, even if some of them look potentially commercial, a very small percentage will result in any financial movement.

Websites built for the sole purpose to exploit a yet to be covered hole of an online niche should do so by offering valuable services, products or information. Those that don't will eventually get filtered out of the search engine database.

Some data that search engines use to determine the quality of a website:

Click Through Rate
The number of times a user clicks on the result that represents the website once it is displayed.

Bounce Rate
The percentage of users clicking the Back button, closing their browser, i.e. leaving the site virtually immediately after it loads.

Keyword Co-Occurrence
A gauge that would rank different web documents of different topics, in between being uninformative ( missing phrases of key importance ), authoritative, and spam ( too many related phrases )

Off-site relevancy, Link popularity, Link relevancy
The quality of references to a website on the Internet. Text links with relevant anchor text, from relevant and trusted sources, to relevant and well maintained pages. The number of irrelevant links, links from low quality websites will not raise relevancy. Websites that don't have any quality links supporting its topics will not rank for them.

A couple of other factors also continuously double-check the indexed pages, are matching them up to standards, and these base sets aren't decided by the search engines. The scripts are analyzing the documents and comparing them to standards that were the average derived from websites considered high quality by experts, users, and based on other factors such as accessibility, usability.