Web directory is a directory for the Internet. It organizes submitted web sites into category.
Today, submitting web sites into web directory is a common pratice for Search Engine Optimization (SEO) to generate back-links to improve the web site's Page Rank, and afterall, to have a better Search Engine Result Pages (SERP).

Lets say, you are the owner of an online store that sells health product. Your price is competitive and your product is outstanding. But how can you attract customer to visit your site to purchase your prodcut? One thing you can do would be placing an ad to a heavy traffic search engine company that provides Cost-Per-Click (CPC) advertising program, like Google, Yahoo! or MSN. When a customer searching for a keyword related "health prodcut", your ad will appear. If, for instance, the average cost per click is $0.5, to have 1000 visitors visit your web site would cost $500.

When a visitor searching for a keyword, usually the visitor will only click onto the web sites display on the first page. If your website appears on the first page, then your SERP is 1. So, for instance, there are average 10,000 people search for the keyword "health prodcut" in a month. If your SERP is 1, there's possibility that you would receive 10,000 extra visitors to your web site without any extra cost!

There are couple important factors. The first one is the keywords in your web site. If there isn't any description or keywords related to the prodcut that you are selling, how can visitor find your web site through search engine? Another factor would be your site attribute. Usually, a popular web site would recieve more inbound links from other web sites for references. Google designed an algorithm called PageRank to decide which web page is more important (more inbound links) than the other, which more likely to appear at the top of the search results.

Page Rank is like a voting system. when a web page link to another one, it "casted" a vote to the other web page. In theory, the more inboud links (votes) a page receieve, the higher Page Rank the web page would have, but that is not exactly correct. Some Search Engine Optimization (SEO) company would offer, for a fee, to place your submitted site to hundreds of their web sites automatically. Those sites are considered to be "link farms", which are penalize by major search engine company, like Google, and will not help your web page to increase its Page Rank.

All web sites submitted to Web Directory Plus are human-reviewed. To ensure the directory's quality, our team will go through the submitted site's content to make sure it fits into the right category and is information rich. Once approved, your site will display in a category, with its thumbnail image to give the vistors a better idea how your site looks like. Web Directory Plus is an interative web directory, visitor can leave comment about your site, and place a vote if the visitor like your site. By default, we organize the display order of the site by its Page Rank. We only charge a very small one-time administration fee for submitted site for regular listing.

For more information about Page Rank, you can read the article from Google's Technology Overview for more details. Web Directory Plus has its own PageRank Checker. To check your web page' Page Rank, welcome to use it on Page Rank Checker area. To have your own Page Rank Checker tool, follow the instruction in Page Rank Tool to install the Page Rank Checker tool on your web site.