I’ve been doing some thinking about directories and how they’ve managed to get around the problem of selling links. The funny part is they do it while not trying to hide the fact that there only purpose is getting you backlinks. You can go to any SEO forum and get a list of directories along with their PR.
There are websites dedicated to checking and letting you know which directories are search engine friendly (another words pass PR) and companies dedicated to getting you as many links while altering the anchor text and descriptions to get the maxima benefit out of the directories.
The only time anyone uses a directory is when they are looking to add backlinks to their site. How many directories have you gone to and said, MAN, this directory is so good I’m going to bookmark it?
A good link is one that brings good traffic and visitors that do something you desire while on your website. Blog comments, forum posting, photo sharing and other social media sites can send these types of visitors but I’ve never seen anyone say submit your site to this directory for the traffic.
I do submit my site to directories but what unique value do I get from these directories? None or at least this is my own observation. However I submit my sites to directories for the backlinks they can send my site and in turn boost my PR and my ranking in the search engines.
Google says buying links are bad yet directories continue to sell them. How is it that directories get around the algo tweaks while real sites continue having to make changes to keep Google happy?
Google has stated that paid links should not pass PR, so in all fairness should paid directory links pass PR?
Google has forced blogging platforms to add nofollow tags to their software as well as sites like W3C and Wikipedia and others to add nofollow tags to all outgoing links. I’ve also recently heard that Google has figured out a way not to count links coming from blogrolls, yet directories continue to sell links and pass PR.
Don’t get me wrong, I’m not complaining and I enjoy the boost in PR that directories send. However I have to wonder if I should be worried about a future algo tweak that could very well discount the links coming from directories. Or do directories somehow have a special place in Google’s heart that allows them to break rules that other sites have to obey?

Janeth,
These are some great points. I totally agree.
Google does suggest to submit your site to directories. I sometimes wonder if google is trying to get directory owners to help with the “Screening of sites”.
For example if you own a reputable directory, you’re going to delete all links you think are crap links. So directory owners are telling google: “Hey, I checked these sites out for you; no need to waste your time checking them out.” This helps google because if it’s in a good directory, then it means someone should have at least checked it out.
Carl