Search Engine Overview

Search engines are an extremely powerful way of promoting your website online.  Consider them your silent Public Relations firm, quietly working in the background. Many studies have shown that between 40% and 80% of users found what they were looking for by using the search engine feature of the Internet.

According to Search Engine Watch ( – 6.8 billion searches were performed in April 2007.

The great thing about search engines is they bring targeted traffic to your website. These people are already motivated to make a purchase from you- because they searched you out.

With the right website optimisation, the search engines can always deliver your site to your audiences.

Search Engine Types

Crawler-Based Search Engines

Crawler-based search engines use automated software programs to survey and categorise web pages.  The programs used by the search engines to access your web pages are called ‘spiders’, ‘crawlers’, ‘robots’ or ‘bots’.

A spider will find a web page, download it and analyse the information presented on the web page.  This is usually an automated process. The web page will then be added to the search engine’s database.  Then when a user performs a search, the search engine will check its database of web pages for the key words the user searched on to present a list of link results. 

The results (list of suggested links to go to), are listed on pages by order of which is ‘closest’ (as defined by the search engine), to what the user wants to find online.

Crawler-based search engines are constantly searching the Internet for new web pages and updating their database of information with these new or altered pages.

Examples of crawler-based search engines are:



A ‘directory’ uses human editors who decide what category the site belongs to; they place websites within specific categories in the ‘directories’ database.  The human editors comprehensively check the website and rank it, based on the information they find, using a pre-defined set of rules.

As of April 2007, there are two major international directories:

Note:  Since late 2002 Yahoo has provided search results using crawler-based technology as well as its own directory.


Hybrid Search Engines

Hybrid search engines use a combination of both crawler-based results and directory results.  More and more search engines these days are moving to a hybrid-based model.  Examples of hybrid search engines are:

Meta Search Engines

Meta search engines take the results from all the other search engines results, and combine them into one large listing.  Examples of Meta search engines include:


Specialty Search Engines

Specialty search engines have been developed to cater for the demands of niche areas.  There are many specialty search engines, including:

  •  And so on


The Dominant Search Engines & Directories

The key search engines that you need to be aware of are (ranked in order of priority):


  • Google (
    Google is the biggest and most popular search engine on the Internet.  According to Nielsen/NetRatings, in April 2007 Google served up a huge 3.8 billion searches - 55.2% of all searches!
  • Yahoo (
    Yahoo is the second-largest search engine and offers a wide range of other value-add services too.  The Yahoo website is considered by many authorities (Alexa and others) to be the busiest website in the world.  Nielsen/NetRatings reports that in the month of April 2007, Yahoo served up 1.5 billion searches - 21.9% of all searches.
  • Windows Live / MSN (
    Windows Live is the third-largest search engine.  Windows Live achieves much of its popularity because it is provided as the default search engine when using Microsoft Windows.  According to Nielsen/NetRatings, in the month of April 2007, Windows Live served up 613 million searches - 9% of all searches.
  • SearchNZ (
    SearchNZ is a specialty search engine for finding New Zealand websites.

The key directories that you need to be aware of are (ranked in order of priority):

  • Open Directory Project (
    The Open Directory Project is a free directory maintained by over 75,000 volunteer editors (as at April 2007). The ODP is used by Google and some smaller search engines to provide directory results for their customers.
  • Yahoo (
    Yahoo originally started as a commercial directory before becoming a predominately crawler-based search engine in late 2002.  The Yahoo Directory is maintained by a number of paid editorial staff and the results are used within Yahoo Search and many other search engines affiliated with Yahoo.

The following are currently the key NZ-based directories; they maintain their listings using paid editorial staff that ensure that the coded key words and phrases are relevant 'search-wise' to your product or service before adding to the directory: