I have submitted my site to about 100 link directories, but I don't find that any of them appear when I use my Google Webmaster Tools to view external links to my site.

Do they help Page Rank?

I set one up myself actually (link in sig) to help myself an others with more inbound links, but if it's not helping with Google PR, it kind of seems like a waste of time, no?

Does anyone have experience with this?

Link directories are also known as link farms. Linking to link farms is not recommended since many of them may not be relevant in content to your site and will be rated accordingly by the search engine crawler.

So you should search for directories which are content specific then? Or not at all?

As far as I know, niche related directory submission will help to get more PR as well as traffic too. Specially, when you submit a site, if you can choose the right category that is more than enough too. :)

As an SEO expert I met once on an Amtrak train told me, "Becareful where you park your website. If you park it on a bad neighborhood, you may undesired results." This is very relevant to link directories. Becareful where you link to.

If you get a backlink without having to reciprocate, it shouldn't hurt you though in theory, right?

The backlink will help you especially if it is coming from a well respected site.

Choose the directories for submission which constantly indexed by Google and visible in search engine result pages. There is wastage of time if you add your resource to dead directories.

Relevant directory is very helpful to get visitors for your site.

Very helpfull for raise Page Rank.

I think the directories are getting little importance, however the directories that have good reputation and having higher page rank would worth for submission.

I totally agree with you BobChrist. It really matters where the link is "parked at" rather than quantity.

I have created my own directory which is being indexed with Google, so I suppose links there are useful.

a lot of those directories with the Higher PR are now paying directories. I think getting into Free directories that are just starting to build may be worth it, because if they develop into high PR directories and you were in it when it was lower, and they didn't charge, it might benefit you long term.

hey ... its quite right that submitting site to directory for a same theme or niche is quite gaining in terms of pr .. but you should also think about other options like social bookmarking , press release , article submission sites. As only directory submission is just a one factor of increasing a pr or getting inbound links or visaversa

Results depend upon the reliability of the data. Also, you must select only the product relevant directories. Plz check the meta tags also, don’t keep too many. Directory submission definitely helps in PR improvement.

Agree with others, you should still be careful about which directory you submit to.

I think relevancy is everything.

Is relevant directories key, or just relevant categories within a directory?

It is also wise to measure the PR of the site as well as the PR of the page where your link is listed. The higher the better.

Yes, link directories are important for SEO. The more important is to select the right sites, where you leave your site link. PR, relevancy, quality of the content, type of visitors are the main aspects to be considered.

hi...
well ya they do help depending on the directories u r using to submit ur link directories should be active to entertain your link otherwise off course no use to submit!

I think the PR of the directory is v important as back links are concerned.