A and B of SEO

There are two types of search engines: Search Engine Directories and Search Engine Spiders. Each search engine (regardless of whether it is a spider or a directory) uses unique criteria for "ranking" websites.

1. Search Engine Directories rely on humans to gauge web page relevancy and search engine placement. Human editors review each website and rank them according to a set of guidelines such as website content, website functionality, and design professionalism. Yahoo! and the Open Directory Project, DMOZ are the most popular Directory Driven Search Engines.

2. Spider driven search engines use "robots" to spider websites across the Internet. Robots "crawl" each website and "score" pages based on relevancy. Some engines score the index page while others score individual web pages. A website's score or placement within a spider driven search engine is derived from hundreds of variables such as, link popularity, click popularity, keyword density, website themes and more. Google.com is the most popular spider driven search engine.

Earning Top 10 Search Engine Placement is complex and highly competitive for three reasons:

1. The variety and complexity of search engine's "ranking" algorithms
2. Search Engines constantly modify "page ranking criterions"
3. Increasing competition on the web