note: edited June 25th.

The following are some of the major factors that you can use to judge the quality of a web directory. SEO factors are the main focus of this article.

Links should pass PageRank.

Links should share PR with the site listed.  For example, links should not use JavaScript type redirection techniques, should not have nofollow attributes and should not be excludes by robots.txt.

Directory is ranked highly by the Search Engines

The directory should be well indexed by the search engines, especially Google.  Ideally a directory should rank high in Google for a number of different keyword phrases.  A site that ranks well in the SERPs (search engine results) is likely a good candidate to pass on PageRank.

The directory’s Google cache dates should be recent (including its main category pages).

Unique content

Unique content is a plus for any website, including directories.  Without unique content the Search Engines have little motivation to index the directory.   Since many directories tend to have many of the same sites listed, with the same titles and descriptions unique content can be a challenge.   Apart from the directory, any additional pages of unique content on the website can only help.  If the content is useful, it can bring in some useful organic natural links.

I have noticed a problem that has gotten worse of late.  Instead of creating their own categories, general directory owners are using scripts of ready-made categories.  I estimate that there are 500 directories using one popular category dump.  Some owners make huge networks of directories.  Why make 1 directory when you can make 50 or maybe 150.   These sites are often similar or exactly the same.   The worst situation is an owner offering to list your site on a large amount of directories for a fixed price.  These directories will often have nothing but duplicate content.

Hosting on unique IPs

Most directories use shared hosting, which does not pose any problems.   The problem occurs when an owner hosts a large amount of directories o the same IP.   There are many large network of directories hosted on the same IP or the same IP c class.   I have seen networks exceeding 250 directories.  From my experience the majority of these never rise above PR0 or N/A.   Here are some examples from our listings.

http://web-directories.ws/General/Free/page-73.html

http://web-directories.ws/General/Free/page-74.html

http://web-directories.ws/Niche/Real_Estate/page-5.html

Eventually, a good portion of these are allowed to die. It could be that Google does not like networks of sites.  It could be the duplicate IPs.  It could be the duplicate content.  It could simply that an owner of 100 cookie cutter directories does not put much care into running and promoting each individual site.

Regardless of the reason, I have found that networks hosted on the same IP are a poor sign of quality and a good indicator of a poor future for the directories.

Age of site

All else being equal, older sites have always done better in the search engines.  Google is very dedicated to fighting spam.   It is reasonable to assume that older sites have a better change to being trusted than new ones.

Age as a directory

Directories are often created using dropped domains that have PageRank.   Since this practice happens frequently, it is safe to assume that Google can identify this change

Quantity and quality of inbound links

A good directory would have a good number of quality inbound links.  The number of links from different domains and different IPs would be more important than the total number of links.  For niche or regional directories links from the specific niche or region would be advantageous.

Directory’s pages have unique titles, meta descriptions and meta keywords.

Some software, especially the free versions, does not have the capabilities to create unique title and meta tags for internal pages.  In other cases, directories do not make the extra effort to make categories unique or they do not understand its importance.

Solid editing standards

A quality directory would provide consistent editing of listings.  “Google trusts sites less when they link to spammy sites or bad neighborhoods” (Matt Cutts). They would also re-edit listings over time to ensure that the nature of the site has not changed.  The directory should also remove dead links periodically.  Unfortunately this criterion is hard to quantify on its own without extensive review of the directory’s listings.  You can do a quick look for obviously spammy sites.

Ideally, a directory’s “acceptance rules” should be clearly posted on the site.

Clean category Structures

The categories should be well-designed with deep sub-categories.   A directory with weak categories will not be able to handle the volume of submissions over time.   There should be listings in the category you want to submit your site to.  There is also a possibility that a link will be worth more if it surrounded by similar sites and related text.

On the other hand, over 50 listings on a page are probably too much. The categories should not be convoluted by excess ads and popups.

Traffic

High traffic would be nice but don’t expect it from most directories, especially the free ones.  There are a couple of well established paid directories that could bring you some traffic.

Reasonably fast reviews

Paid directories are held to a much higher standard than free directories.  Directories that never get around to approving their free submissions should be avoided.

Support – easily available and friendly

Contact information should be easily found on the directory.  As with any business, you should expect a courteous response to your queries within a reasonable period of time.

Good design

A good, original design means that the owner has put effort into building the site.  This quality factor means that there is a better chance that the directory will be around for the long-run.

Your comments would be appreciated.

Publishers:  If you would like to republish this article please contact me with your request and where it will reside, and I’ll send you a short bio you can use with it on your site.