Jeff Behrendt recently offered some great advice over at Search Engine Journal in 7 Costly Mistakes Webmasters Make About Web Directories.
One of the points that really should be emphasized is the mistake of not varying your anchor text and descriptions:
Costly Mistake #5 – Not varying anchor text and descriptions. From what I’ve seen, a lot of submitters seem to use the same anchor text and description for all of their directory submissions. My editors spend a large amount of time re-writing this. A good way to set up a red flag with Google is suddenly to gain a lot of links to your site with the exact same anchor text and the exact same surrounding text. Ideally, all of your directory submissions should use unique wording. At the very least, have several versions of anchor text and descriptions that you use when submitting to directories.
Consider the possible consequence of replicating the same listing hundreds of times over (think duplicate content/supplemental results) and it’s easy to see how you’re contributing to the probability that the listing/link will provide you with little if any benefit.
Many complain that submitting to free directories is a waste of time as they don’t provide any boost or juice, yet they don’t try to maximize the potential when submitting.
