About Search Engines and Directories
Search Engines
Search engines are databases of web pages which have been indexed (listed) by automatic tools which crawl the web looking for new pages to index. These tools are called spiders, crawlers or robots. In theory, any web page will be found, providing it has at least one link to it from other page. But the process can be speeded up by submitting your site to be indexed. If you change your web pages, crawler-based search engines eventually find these changes, and that can affect how you are listed. Page titles, page text and inbound links all play a role in ranking.
Directories
Directories are lists of sites which have been reviewed and catalogued into a hierarchical structure by human editors. The only way to have a site reviewed for inclusion in a directory is to submit the site to them. Quality sites with good content are more likely to get listed than poor sites. Things that are useful for improving a listing with a search engine have nothing to do with improving a listing in a directory.
Paid Inclusion Programmes
Some engines (eg Yahoo) have programmes that guarantee to add the pages you submit quickly. The downside to some of these paid inclusion programmes is that you may be charged every time someone clicks on your listing (some don't charge this way). If you run out of money in your account, potentially, your listing may be dropped. Paid inclusion does not usually guarantee better ranking..
Paid Placement Programmes
Some engines charge according to how you want your site to rank for a particular search phrase. You bid for a search term and position and then pay everytime a user 'click through' to your site - sometimes called a "pay-per-click" (PPC) or a "cost-per-click" (CPC) search engine.
The two main paid placement programmes are Yahoo Sponsored Search and Google Adwords. Major second tier PPC players include Espotting.com, Findwhat.com and Kanoodle.com.
These programmes may be worthwhile if your site is not ranking in the generic search engine results as you would like. This form of search engine advertising means that you can be guaranteed to appear in the top results for the terms you are interested in within a day or less. Given this, paid listings are an option that should be explored by site owners who wish to quickly build visibility. They may also be a long-term advertising option for some. They will work best if you manage them closely on a regular basis.
The search engine and directory situation changes almost daily. The information here is up to date as of May 2007. Tomorrow it could be different... Following is information and links to some of the major search engines and directories.
Major Search Engines